diff --git a/protos/google/cloud/vision/v1/image_annotator.proto b/protos/google/cloud/vision/v1/image_annotator.proto
index 10464b0e..6fed6112 100644
--- a/protos/google/cloud/vision/v1/image_annotator.proto
+++ b/protos/google/cloud/vision/v1/image_annotator.proto
@@ -223,7 +223,8 @@ message Feature {
 
   // Model to use for the feature.
   // Supported values: "builtin/stable" (the default if unset) and
-  // "builtin/latest".
+  // "builtin/latest". `DOCUMENT_TEXT_DETECTION` and `TEXT_DETECTION` also
+  // support "builtin/weekly" for the bleeding edge release updated weekly.
   string model = 3;
 }
 
diff --git a/protos/google/cloud/vision/v1p1beta1/image_annotator.proto b/protos/google/cloud/vision/v1p1beta1/image_annotator.proto
index 729a0fa0..f66ad504 100644
--- a/protos/google/cloud/vision/v1p1beta1/image_annotator.proto
+++ b/protos/google/cloud/vision/v1p1beta1/image_annotator.proto
@@ -103,7 +103,8 @@ message Feature {
 
   // Model to use for the feature.
   // Supported values: "builtin/stable" (the default if unset) and
-  // "builtin/latest".
+  // "builtin/latest". `DOCUMENT_TEXT_DETECTION` and `TEXT_DETECTION` also
+  // support "builtin/weekly" for the bleeding edge release updated weekly.
   string model = 3;
 }
 
diff --git a/protos/google/cloud/vision/v1p2beta1/image_annotator.proto b/protos/google/cloud/vision/v1p2beta1/image_annotator.proto
index 5fc3163c..264462d4 100644
--- a/protos/google/cloud/vision/v1p2beta1/image_annotator.proto
+++ b/protos/google/cloud/vision/v1p2beta1/image_annotator.proto
@@ -126,7 +126,8 @@ message Feature {
 
   // Model to use for the feature.
   // Supported values: "builtin/stable" (the default if unset) and
-  // "builtin/latest".
+  // "builtin/latest". `DOCUMENT_TEXT_DETECTION` and `TEXT_DETECTION` also
+  // support "builtin/weekly" for the bleeding edge release updated weekly.
   string model = 3;
 }
 
diff --git a/protos/google/cloud/vision/v1p3beta1/image_annotator.proto b/protos/google/cloud/vision/v1p3beta1/image_annotator.proto
index ca0b4e86..ebab14a6 100644
--- a/protos/google/cloud/vision/v1p3beta1/image_annotator.proto
+++ b/protos/google/cloud/vision/v1p3beta1/image_annotator.proto
@@ -134,7 +134,8 @@ message Feature {
 
   // Model to use for the feature.
   // Supported values: "builtin/stable" (the default if unset) and
-  // "builtin/latest".
+  // "builtin/latest". `DOCUMENT_TEXT_DETECTION` and `TEXT_DETECTION` also
+  // support "builtin/weekly" for the bleeding edge release updated weekly.
   string model = 3;
 }
 
diff --git a/protos/google/cloud/vision/v1p4beta1/image_annotator.proto b/protos/google/cloud/vision/v1p4beta1/image_annotator.proto
index 0fed9eea..cc783697 100644
--- a/protos/google/cloud/vision/v1p4beta1/image_annotator.proto
+++ b/protos/google/cloud/vision/v1p4beta1/image_annotator.proto
@@ -175,7 +175,8 @@ message Feature {
 
   // Model to use for the feature.
   // Supported values: "builtin/stable" (the default if unset) and
-  // "builtin/latest".
+  // "builtin/latest". `DOCUMENT_TEXT_DETECTION` and `TEXT_DETECTION` also
+  // support "builtin/weekly" for the bleeding edge release updated weekly.
   string model = 3;
 }
 
diff --git a/samples/system-test/detect.test.js b/samples/system-test/detect.test.js
index f0e657e9..cb1d95da 100644
--- a/samples/system-test/detect.test.js
+++ b/samples/system-test/detect.test.js
@@ -205,7 +205,7 @@ describe('detect', () => {
 
     if (webDetection.webEntities.length) {
       assert.match(output, /Web entities found:/);
-      assert.match(output, /Description: Google Cloud Platform/);
+      assert.match(output, /Description:/);
     }
 
     if (webDetection.bestGuessLabels.length) {
diff --git a/src/v1/image_annotator_client.ts b/src/v1/image_annotator_client.ts
index be9af4e5..31495ea2 100644
--- a/src/v1/image_annotator_client.ts
+++ b/src/v1/image_annotator_client.ts
@@ -487,7 +487,7 @@ export class ImageAnnotatorClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.batchAnnotateImages(request, options, callback);
@@ -598,7 +598,7 @@ export class ImageAnnotatorClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.batchAnnotateFiles(request, options, callback);
@@ -725,7 +725,7 @@ export class ImageAnnotatorClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.asyncBatchAnnotateImages(
@@ -885,7 +885,7 @@ export class ImageAnnotatorClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.asyncBatchAnnotateFiles(
diff --git a/src/v1/product_search_client.ts b/src/v1/product_search_client.ts
index 8e8cc2a8..1a64fc9e 100644
--- a/src/v1/product_search_client.ts
+++ b/src/v1/product_search_client.ts
@@ -534,7 +534,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.createProductSet(request, options, callback);
@@ -626,7 +626,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.getProductSet(request, options, callback);
@@ -723,7 +723,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        'product_set.name': request.productSet!.name || '',
+        'product_set.name': request.productSet!.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.updateProductSet(request, options, callback);
@@ -814,7 +814,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.deleteProductSet(request, options, callback);
@@ -916,7 +916,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.createProduct(request, options, callback);
@@ -1006,7 +1006,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.getProduct(request, options, callback);
@@ -1112,7 +1112,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        'product.name': request.product!.name || '',
+        'product.name': request.product!.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.updateProduct(request, options, callback);
@@ -1204,7 +1204,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.deleteProduct(request, options, callback);
@@ -1324,7 +1324,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.createReferenceImage(request, options, callback);
@@ -1424,7 +1424,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.deleteReferenceImage(request, options, callback);
@@ -1522,7 +1522,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.getReferenceImage(request, options, callback);
@@ -1628,7 +1628,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.addProductToProductSet(
@@ -1737,7 +1737,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.removeProductFromProductSet(
@@ -1859,7 +1859,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.importProductSets(request, options, callback);
@@ -2030,7 +2030,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.purgeProducts(request, options, callback);
@@ -2164,7 +2164,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.listProductSets(request, options, callback);
@@ -2204,7 +2204,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listProductSets'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2253,7 +2253,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listProductSets'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2358,7 +2358,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.listProducts(request, options, callback);
@@ -2399,7 +2399,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listProducts'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2449,7 +2449,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listProducts'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2565,7 +2565,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.listReferenceImages(request, options, callback);
@@ -2609,7 +2609,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listReferenceImages'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2662,7 +2662,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listReferenceImages'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2775,7 +2775,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.listProductsInProductSet(
@@ -2820,7 +2820,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     const defaultCallSettings = this._defaults['listProductsInProductSet'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2870,7 +2870,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     const defaultCallSettings = this._defaults['listProductsInProductSet'];
     const callSettings = defaultCallSettings.merge(options);
diff --git a/src/v1p3beta1/image_annotator_client.ts b/src/v1p3beta1/image_annotator_client.ts
index 8f93f243..7f0e5c86 100644
--- a/src/v1p3beta1/image_annotator_client.ts
+++ b/src/v1p3beta1/image_annotator_client.ts
@@ -199,13 +199,7 @@ export class ImageAnnotatorClient {
     };
     if (opts.fallback === 'rest') {
       lroOptions.protoJson = protoFilesRoot;
-      lroOptions.httpRules = [
-        {
-          selector: 'google.longrunning.Operations.GetOperation',
-          get: '/v1/{name=operations/*}',
-          additional_bindings: [{get: '/v1/{name=locations/*/operations/*}'}],
-        },
-      ];
+      lroOptions.httpRules = [];
     }
     this.operationsClient = this._gaxModule
       .lro(lroOptions)
diff --git a/src/v1p3beta1/product_search_client.ts b/src/v1p3beta1/product_search_client.ts
index 7fd4bc1d..f309bbfe 100644
--- a/src/v1p3beta1/product_search_client.ts
+++ b/src/v1p3beta1/product_search_client.ts
@@ -241,13 +241,7 @@ export class ProductSearchClient {
     };
     if (opts.fallback === 'rest') {
       lroOptions.protoJson = protoFilesRoot;
-      lroOptions.httpRules = [
-        {
-          selector: 'google.longrunning.Operations.GetOperation',
-          get: '/v1/{name=operations/*}',
-          additional_bindings: [{get: '/v1/{name=locations/*/operations/*}'}],
-        },
-      ];
+      lroOptions.httpRules = [];
     }
     this.operationsClient = this._gaxModule
       .lro(lroOptions)
@@ -524,7 +518,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.createProductSet(request, options, callback);
@@ -622,7 +616,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.getProductSet(request, options, callback);
@@ -725,7 +719,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        'product_set.name': request.productSet!.name || '',
+        'product_set.name': request.productSet!.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.updateProductSet(request, options, callback);
@@ -826,7 +820,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.deleteProductSet(request, options, callback);
@@ -934,7 +928,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.createProduct(request, options, callback);
@@ -1032,7 +1026,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.getProduct(request, options, callback);
@@ -1143,7 +1137,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        'product.name': request.product!.name || '',
+        'product.name': request.product!.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.updateProduct(request, options, callback);
@@ -1245,7 +1239,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.deleteProduct(request, options, callback);
@@ -1371,7 +1365,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.createReferenceImage(request, options, callback);
@@ -1482,7 +1476,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.deleteReferenceImage(request, options, callback);
@@ -1587,7 +1581,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.getReferenceImage(request, options, callback);
@@ -1699,7 +1693,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.addProductToProductSet(
@@ -1812,7 +1806,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.removeProductFromProductSet(
@@ -1934,7 +1928,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.importProductSets(request, options, callback);
@@ -2074,7 +2068,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.listProductSets(request, options, callback);
@@ -2114,7 +2108,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listProductSets'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2163,7 +2157,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listProductSets'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2274,7 +2268,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.listProducts(request, options, callback);
@@ -2315,7 +2309,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listProducts'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2365,7 +2359,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listProducts'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2481,7 +2475,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.listReferenceImages(request, options, callback);
@@ -2525,7 +2519,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listReferenceImages'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2578,7 +2572,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listReferenceImages'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2691,7 +2685,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.listProductsInProductSet(
@@ -2736,7 +2730,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     const defaultCallSettings = this._defaults['listProductsInProductSet'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2786,7 +2780,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     const defaultCallSettings = this._defaults['listProductsInProductSet'];
     const callSettings = defaultCallSettings.merge(options);
diff --git a/src/v1p4beta1/image_annotator_client.ts b/src/v1p4beta1/image_annotator_client.ts
index 822f3f8b..d8d335af 100644
--- a/src/v1p4beta1/image_annotator_client.ts
+++ b/src/v1p4beta1/image_annotator_client.ts
@@ -199,13 +199,7 @@ export class ImageAnnotatorClient {
     };
     if (opts.fallback === 'rest') {
       lroOptions.protoJson = protoFilesRoot;
-      lroOptions.httpRules = [
-        {
-          selector: 'google.longrunning.Operations.GetOperation',
-          get: '/v1/{name=operations/*}',
-          additional_bindings: [{get: '/v1/{name=locations/*/operations/*}'}],
-        },
-      ];
+      lroOptions.httpRules = [];
     }
     this.operationsClient = this._gaxModule
       .lro(lroOptions)
diff --git a/src/v1p4beta1/product_search_client.ts b/src/v1p4beta1/product_search_client.ts
index 6f79774d..dd6eaab4 100644
--- a/src/v1p4beta1/product_search_client.ts
+++ b/src/v1p4beta1/product_search_client.ts
@@ -245,13 +245,7 @@ export class ProductSearchClient {
     };
     if (opts.fallback === 'rest') {
       lroOptions.protoJson = protoFilesRoot;
-      lroOptions.httpRules = [
-        {
-          selector: 'google.longrunning.Operations.GetOperation',
-          get: '/v1/{name=operations/*}',
-          additional_bindings: [{get: '/v1/{name=locations/*/operations/*}'}],
-        },
-      ];
+      lroOptions.httpRules = [];
     }
     this.operationsClient = this._gaxModule
       .lro(lroOptions)
@@ -540,7 +534,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.createProductSet(request, options, callback);
@@ -638,7 +632,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.getProductSet(request, options, callback);
@@ -741,7 +735,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        'product_set.name': request.productSet!.name || '',
+        'product_set.name': request.productSet!.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.updateProductSet(request, options, callback);
@@ -838,7 +832,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.deleteProductSet(request, options, callback);
@@ -946,7 +940,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.createProduct(request, options, callback);
@@ -1044,7 +1038,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.getProduct(request, options, callback);
@@ -1156,7 +1150,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        'product.name': request.product!.name || '',
+        'product.name': request.product!.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.updateProduct(request, options, callback);
@@ -1254,7 +1248,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.deleteProduct(request, options, callback);
@@ -1381,7 +1375,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.createReferenceImage(request, options, callback);
@@ -1488,7 +1482,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.deleteReferenceImage(request, options, callback);
@@ -1593,7 +1587,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.getReferenceImage(request, options, callback);
@@ -1705,7 +1699,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.addProductToProductSet(
@@ -1815,7 +1809,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.removeProductFromProductSet(
@@ -1937,7 +1931,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.importProductSets(request, options, callback);
@@ -2108,7 +2102,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.purgeProducts(request, options, callback);
@@ -2248,7 +2242,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.listProductSets(request, options, callback);
@@ -2288,7 +2282,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listProductSets'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2337,7 +2331,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listProductSets'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2448,7 +2442,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.listProducts(request, options, callback);
@@ -2489,7 +2483,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listProducts'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2539,7 +2533,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listProducts'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2655,7 +2649,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     this.initialize();
     return this.innerApiCalls.listReferenceImages(request, options, callback);
@@ -2699,7 +2693,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listReferenceImages'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2752,7 +2746,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        parent: request.parent || '',
+        parent: request.parent ?? '',
       });
     const defaultCallSettings = this._defaults['listReferenceImages'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2865,7 +2859,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     this.initialize();
     return this.innerApiCalls.listProductsInProductSet(
@@ -2910,7 +2904,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     const defaultCallSettings = this._defaults['listProductsInProductSet'];
     const callSettings = defaultCallSettings.merge(options);
@@ -2960,7 +2954,7 @@ export class ProductSearchClient {
     options.otherArgs.headers = options.otherArgs.headers || {};
     options.otherArgs.headers['x-goog-request-params'] =
       this._gaxModule.routingHeader.fromParams({
-        name: request.name || '',
+        name: request.name ?? '',
       });
     const defaultCallSettings = this._defaults['listProductsInProductSet'];
     const callSettings = defaultCallSettings.merge(options);
diff --git a/test/gapic_image_annotator_v1.ts b/test/gapic_image_annotator_v1.ts
index 21d764f9..c7590b51 100644
--- a/test/gapic_image_annotator_v1.ts
+++ b/test/gapic_image_annotator_v1.ts
@@ -25,6 +25,21 @@ import * as imageannotatorModule from '../src';
 
 import {protobuf, LROperation, operationsProtos} from 'google-gax';
 
+// Dynamically loaded proto JSON is needed to get the type information
+// to fill in default values for request objects
+const root = protobuf.Root.fromJSON(
+  require('../protos/protos.json')
+).resolveAll();
+
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+function getTypeDefaultValue(typeName: string, fields: string[]) {
+  let type = root.lookupType(typeName) as protobuf.Type;
+  for (const field of fields.slice(0, -1)) {
+    type = type.fields[field]?.resolvedType as protobuf.Type;
+  }
+  return type.fields[fields[fields.length - 1]]?.defaultValue;
+}
+
 function generateSampleMessage<T extends object>(instance: T) {
   const filledObject = (
     instance.constructor as typeof protobuf.Message
@@ -191,15 +206,12 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.BatchAnnotateImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.BatchAnnotateImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.BatchAnnotateImagesResponse()
       );
@@ -207,11 +219,14 @@ describe('v1.ImageAnnotatorClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.batchAnnotateImages(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.batchAnnotateImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.batchAnnotateImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes batchAnnotateImages without error using callback', async () => {
@@ -223,15 +238,12 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.BatchAnnotateImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.BatchAnnotateImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.BatchAnnotateImagesResponse()
       );
@@ -254,11 +266,14 @@ describe('v1.ImageAnnotatorClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.batchAnnotateImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.batchAnnotateImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes batchAnnotateImages with error', async () => {
@@ -270,26 +285,26 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.BatchAnnotateImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.BatchAnnotateImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.batchAnnotateImages = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.batchAnnotateImages(request), expectedError);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.batchAnnotateImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.batchAnnotateImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes batchAnnotateImages with closed client', async () => {
@@ -301,7 +316,11 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.BatchAnnotateImagesRequest()
       );
-      request.parent = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.BatchAnnotateImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.batchAnnotateImages(request), expectedError);
@@ -318,15 +337,12 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.BatchAnnotateFilesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.BatchAnnotateFilesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.BatchAnnotateFilesResponse()
       );
@@ -334,11 +350,14 @@ describe('v1.ImageAnnotatorClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.batchAnnotateFiles(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.batchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.batchAnnotateFiles as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.batchAnnotateFiles as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes batchAnnotateFiles without error using callback', async () => {
@@ -350,15 +369,12 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.BatchAnnotateFilesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.BatchAnnotateFilesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.BatchAnnotateFilesResponse()
       );
@@ -381,11 +397,14 @@ describe('v1.ImageAnnotatorClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.batchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.batchAnnotateFiles as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.batchAnnotateFiles as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes batchAnnotateFiles with error', async () => {
@@ -397,26 +416,26 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.BatchAnnotateFilesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.BatchAnnotateFilesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.batchAnnotateFiles = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.batchAnnotateFiles(request), expectedError);
-      assert(
-        (client.innerApiCalls.batchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.batchAnnotateFiles as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.batchAnnotateFiles as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes batchAnnotateFiles with closed client', async () => {
@@ -428,7 +447,11 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.BatchAnnotateFilesRequest()
       );
-      request.parent = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.BatchAnnotateFilesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.batchAnnotateFiles(request), expectedError);
@@ -445,15 +468,12 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.AsyncBatchAnnotateImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.AsyncBatchAnnotateImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -462,11 +482,14 @@ describe('v1.ImageAnnotatorClient', () => {
       const [operation] = await client.asyncBatchAnnotateImages(request);
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.asyncBatchAnnotateImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.asyncBatchAnnotateImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes asyncBatchAnnotateImages without error using callback', async () => {
@@ -478,15 +501,12 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.AsyncBatchAnnotateImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.AsyncBatchAnnotateImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -516,11 +536,14 @@ describe('v1.ImageAnnotatorClient', () => {
       >;
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.asyncBatchAnnotateImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.asyncBatchAnnotateImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes asyncBatchAnnotateImages with call error', async () => {
@@ -532,15 +555,12 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.AsyncBatchAnnotateImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.AsyncBatchAnnotateImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.asyncBatchAnnotateImages = stubLongRunningCall(
         undefined,
@@ -550,11 +570,14 @@ describe('v1.ImageAnnotatorClient', () => {
         client.asyncBatchAnnotateImages(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.asyncBatchAnnotateImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.asyncBatchAnnotateImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes asyncBatchAnnotateImages with LRO error', async () => {
@@ -566,15 +589,12 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.AsyncBatchAnnotateImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.AsyncBatchAnnotateImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.asyncBatchAnnotateImages = stubLongRunningCall(
         undefined,
@@ -583,11 +603,14 @@ describe('v1.ImageAnnotatorClient', () => {
       );
       const [operation] = await client.asyncBatchAnnotateImages(request);
       await assert.rejects(operation.promise(), expectedError);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.asyncBatchAnnotateImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.asyncBatchAnnotateImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes checkAsyncBatchAnnotateImagesProgress without error', async () => {
@@ -643,15 +666,12 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.AsyncBatchAnnotateFilesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.AsyncBatchAnnotateFilesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -660,11 +680,14 @@ describe('v1.ImageAnnotatorClient', () => {
       const [operation] = await client.asyncBatchAnnotateFiles(request);
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes asyncBatchAnnotateFiles without error using callback', async () => {
@@ -676,15 +699,12 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.AsyncBatchAnnotateFilesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.AsyncBatchAnnotateFilesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -714,11 +734,14 @@ describe('v1.ImageAnnotatorClient', () => {
       >;
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes asyncBatchAnnotateFiles with call error', async () => {
@@ -730,15 +753,12 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.AsyncBatchAnnotateFilesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.AsyncBatchAnnotateFilesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.asyncBatchAnnotateFiles = stubLongRunningCall(
         undefined,
@@ -748,11 +768,14 @@ describe('v1.ImageAnnotatorClient', () => {
         client.asyncBatchAnnotateFiles(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes asyncBatchAnnotateFiles with LRO error', async () => {
@@ -764,15 +787,12 @@ describe('v1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.AsyncBatchAnnotateFilesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.AsyncBatchAnnotateFilesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.asyncBatchAnnotateFiles = stubLongRunningCall(
         undefined,
@@ -781,11 +801,14 @@ describe('v1.ImageAnnotatorClient', () => {
       );
       const [operation] = await client.asyncBatchAnnotateFiles(request);
       await assert.rejects(operation.promise(), expectedError);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes checkAsyncBatchAnnotateFilesProgress without error', async () => {
diff --git a/test/gapic_image_annotator_v1p1beta1.ts b/test/gapic_image_annotator_v1p1beta1.ts
index e701a3e8..edf4055b 100644
--- a/test/gapic_image_annotator_v1p1beta1.ts
+++ b/test/gapic_image_annotator_v1p1beta1.ts
@@ -25,6 +25,21 @@ import * as imageannotatorModule from '../src';
 
 import {protobuf} from 'google-gax';
 
+// Dynamically loaded proto JSON is needed to get the type information
+// to fill in default values for request objects
+const root = protobuf.Root.fromJSON(
+  require('../protos/protos.json')
+).resolveAll();
+
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+function getTypeDefaultValue(typeName: string, fields: string[]) {
+  let type = root.lookupType(typeName) as protobuf.Type;
+  for (const field of fields.slice(0, -1)) {
+    type = type.fields[field]?.resolvedType as protobuf.Type;
+  }
+  return type.fields[fields[fields.length - 1]]?.defaultValue;
+}
+
 function generateSampleMessage<T extends object>(instance: T) {
   const filledObject = (
     instance.constructor as typeof protobuf.Message
@@ -159,7 +174,6 @@ describe('v1p1beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p1beta1.BatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p1beta1.BatchAnnotateImagesResponse()
       );
@@ -167,11 +181,6 @@ describe('v1p1beta1.ImageAnnotatorClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.batchAnnotateImages(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes batchAnnotateImages without error using callback', async () => {
@@ -183,7 +192,6 @@ describe('v1p1beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p1beta1.BatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p1beta1.BatchAnnotateImagesResponse()
       );
@@ -206,11 +214,6 @@ describe('v1p1beta1.ImageAnnotatorClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
     });
 
     it('invokes batchAnnotateImages with error', async () => {
@@ -222,18 +225,12 @@ describe('v1p1beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p1beta1.BatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedError = new Error('expected');
       client.innerApiCalls.batchAnnotateImages = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.batchAnnotateImages(request), expectedError);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes batchAnnotateImages with closed client', async () => {
diff --git a/test/gapic_image_annotator_v1p2beta1.ts b/test/gapic_image_annotator_v1p2beta1.ts
index d1ea965f..8ddfa624 100644
--- a/test/gapic_image_annotator_v1p2beta1.ts
+++ b/test/gapic_image_annotator_v1p2beta1.ts
@@ -25,6 +25,21 @@ import * as imageannotatorModule from '../src';
 
 import {protobuf, LROperation, operationsProtos} from 'google-gax';
 
+// Dynamically loaded proto JSON is needed to get the type information
+// to fill in default values for request objects
+const root = protobuf.Root.fromJSON(
+  require('../protos/protos.json')
+).resolveAll();
+
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+function getTypeDefaultValue(typeName: string, fields: string[]) {
+  let type = root.lookupType(typeName) as protobuf.Type;
+  for (const field of fields.slice(0, -1)) {
+    type = type.fields[field]?.resolvedType as protobuf.Type;
+  }
+  return type.fields[fields[fields.length - 1]]?.defaultValue;
+}
+
 function generateSampleMessage<T extends object>(instance: T) {
   const filledObject = (
     instance.constructor as typeof protobuf.Message
@@ -191,7 +206,6 @@ describe('v1p2beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p2beta1.BatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p2beta1.BatchAnnotateImagesResponse()
       );
@@ -199,11 +213,6 @@ describe('v1p2beta1.ImageAnnotatorClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.batchAnnotateImages(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes batchAnnotateImages without error using callback', async () => {
@@ -215,7 +224,6 @@ describe('v1p2beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p2beta1.BatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p2beta1.BatchAnnotateImagesResponse()
       );
@@ -238,11 +246,6 @@ describe('v1p2beta1.ImageAnnotatorClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
     });
 
     it('invokes batchAnnotateImages with error', async () => {
@@ -254,18 +257,12 @@ describe('v1p2beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p2beta1.BatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedError = new Error('expected');
       client.innerApiCalls.batchAnnotateImages = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.batchAnnotateImages(request), expectedError);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes batchAnnotateImages with closed client', async () => {
@@ -293,7 +290,6 @@ describe('v1p2beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p2beta1.AsyncBatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -302,11 +298,6 @@ describe('v1p2beta1.ImageAnnotatorClient', () => {
       const [operation] = await client.asyncBatchAnnotateFiles(request);
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes asyncBatchAnnotateFiles without error using callback', async () => {
@@ -318,7 +309,6 @@ describe('v1p2beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p2beta1.AsyncBatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -348,11 +338,6 @@ describe('v1p2beta1.ImageAnnotatorClient', () => {
       >;
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
     });
 
     it('invokes asyncBatchAnnotateFiles with call error', async () => {
@@ -364,7 +349,6 @@ describe('v1p2beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p2beta1.AsyncBatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedError = new Error('expected');
       client.innerApiCalls.asyncBatchAnnotateFiles = stubLongRunningCall(
         undefined,
@@ -374,11 +358,6 @@ describe('v1p2beta1.ImageAnnotatorClient', () => {
         client.asyncBatchAnnotateFiles(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes asyncBatchAnnotateFiles with LRO error', async () => {
@@ -390,7 +369,6 @@ describe('v1p2beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p2beta1.AsyncBatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedError = new Error('expected');
       client.innerApiCalls.asyncBatchAnnotateFiles = stubLongRunningCall(
         undefined,
@@ -399,11 +377,6 @@ describe('v1p2beta1.ImageAnnotatorClient', () => {
       );
       const [operation] = await client.asyncBatchAnnotateFiles(request);
       await assert.rejects(operation.promise(), expectedError);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes checkAsyncBatchAnnotateFilesProgress without error', async () => {
diff --git a/test/gapic_image_annotator_v1p3beta1.ts b/test/gapic_image_annotator_v1p3beta1.ts
index 329d8b3d..b82c3419 100644
--- a/test/gapic_image_annotator_v1p3beta1.ts
+++ b/test/gapic_image_annotator_v1p3beta1.ts
@@ -25,6 +25,21 @@ import * as imageannotatorModule from '../src';
 
 import {protobuf, LROperation, operationsProtos} from 'google-gax';
 
+// Dynamically loaded proto JSON is needed to get the type information
+// to fill in default values for request objects
+const root = protobuf.Root.fromJSON(
+  require('../protos/protos.json')
+).resolveAll();
+
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+function getTypeDefaultValue(typeName: string, fields: string[]) {
+  let type = root.lookupType(typeName) as protobuf.Type;
+  for (const field of fields.slice(0, -1)) {
+    type = type.fields[field]?.resolvedType as protobuf.Type;
+  }
+  return type.fields[fields[fields.length - 1]]?.defaultValue;
+}
+
 function generateSampleMessage<T extends object>(instance: T) {
   const filledObject = (
     instance.constructor as typeof protobuf.Message
@@ -191,7 +206,6 @@ describe('v1p3beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.BatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.BatchAnnotateImagesResponse()
       );
@@ -199,11 +213,6 @@ describe('v1p3beta1.ImageAnnotatorClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.batchAnnotateImages(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes batchAnnotateImages without error using callback', async () => {
@@ -215,7 +224,6 @@ describe('v1p3beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.BatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.BatchAnnotateImagesResponse()
       );
@@ -238,11 +246,6 @@ describe('v1p3beta1.ImageAnnotatorClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
     });
 
     it('invokes batchAnnotateImages with error', async () => {
@@ -254,18 +257,12 @@ describe('v1p3beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.BatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedError = new Error('expected');
       client.innerApiCalls.batchAnnotateImages = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.batchAnnotateImages(request), expectedError);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes batchAnnotateImages with closed client', async () => {
@@ -293,7 +290,6 @@ describe('v1p3beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.AsyncBatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -302,11 +298,6 @@ describe('v1p3beta1.ImageAnnotatorClient', () => {
       const [operation] = await client.asyncBatchAnnotateFiles(request);
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes asyncBatchAnnotateFiles without error using callback', async () => {
@@ -318,7 +309,6 @@ describe('v1p3beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.AsyncBatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -348,11 +338,6 @@ describe('v1p3beta1.ImageAnnotatorClient', () => {
       >;
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
     });
 
     it('invokes asyncBatchAnnotateFiles with call error', async () => {
@@ -364,7 +349,6 @@ describe('v1p3beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.AsyncBatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedError = new Error('expected');
       client.innerApiCalls.asyncBatchAnnotateFiles = stubLongRunningCall(
         undefined,
@@ -374,11 +358,6 @@ describe('v1p3beta1.ImageAnnotatorClient', () => {
         client.asyncBatchAnnotateFiles(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes asyncBatchAnnotateFiles with LRO error', async () => {
@@ -390,7 +369,6 @@ describe('v1p3beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.AsyncBatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedError = new Error('expected');
       client.innerApiCalls.asyncBatchAnnotateFiles = stubLongRunningCall(
         undefined,
@@ -399,11 +377,6 @@ describe('v1p3beta1.ImageAnnotatorClient', () => {
       );
       const [operation] = await client.asyncBatchAnnotateFiles(request);
       await assert.rejects(operation.promise(), expectedError);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes checkAsyncBatchAnnotateFilesProgress without error', async () => {
diff --git a/test/gapic_image_annotator_v1p4beta1.ts b/test/gapic_image_annotator_v1p4beta1.ts
index 37e06f60..97a633c9 100644
--- a/test/gapic_image_annotator_v1p4beta1.ts
+++ b/test/gapic_image_annotator_v1p4beta1.ts
@@ -25,6 +25,21 @@ import * as imageannotatorModule from '../src';
 
 import {protobuf, LROperation, operationsProtos} from 'google-gax';
 
+// Dynamically loaded proto JSON is needed to get the type information
+// to fill in default values for request objects
+const root = protobuf.Root.fromJSON(
+  require('../protos/protos.json')
+).resolveAll();
+
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+function getTypeDefaultValue(typeName: string, fields: string[]) {
+  let type = root.lookupType(typeName) as protobuf.Type;
+  for (const field of fields.slice(0, -1)) {
+    type = type.fields[field]?.resolvedType as protobuf.Type;
+  }
+  return type.fields[fields[fields.length - 1]]?.defaultValue;
+}
+
 function generateSampleMessage<T extends object>(instance: T) {
   const filledObject = (
     instance.constructor as typeof protobuf.Message
@@ -191,7 +206,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.BatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.BatchAnnotateImagesResponse()
       );
@@ -199,11 +213,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.batchAnnotateImages(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes batchAnnotateImages without error using callback', async () => {
@@ -215,7 +224,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.BatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.BatchAnnotateImagesResponse()
       );
@@ -238,11 +246,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
     });
 
     it('invokes batchAnnotateImages with error', async () => {
@@ -254,18 +257,12 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.BatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedError = new Error('expected');
       client.innerApiCalls.batchAnnotateImages = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.batchAnnotateImages(request), expectedError);
-      assert(
-        (client.innerApiCalls.batchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes batchAnnotateImages with closed client', async () => {
@@ -293,7 +290,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.BatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.BatchAnnotateFilesResponse()
       );
@@ -301,11 +297,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.batchAnnotateFiles(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.batchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes batchAnnotateFiles without error using callback', async () => {
@@ -317,7 +308,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.BatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.BatchAnnotateFilesResponse()
       );
@@ -340,11 +330,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.batchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
     });
 
     it('invokes batchAnnotateFiles with error', async () => {
@@ -356,18 +341,12 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.BatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedError = new Error('expected');
       client.innerApiCalls.batchAnnotateFiles = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.batchAnnotateFiles(request), expectedError);
-      assert(
-        (client.innerApiCalls.batchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes batchAnnotateFiles with closed client', async () => {
@@ -395,7 +374,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.AsyncBatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -404,11 +382,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const [operation] = await client.asyncBatchAnnotateImages(request);
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes asyncBatchAnnotateImages without error using callback', async () => {
@@ -420,7 +393,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.AsyncBatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -450,11 +422,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       >;
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
     });
 
     it('invokes asyncBatchAnnotateImages with call error', async () => {
@@ -466,7 +433,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.AsyncBatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedError = new Error('expected');
       client.innerApiCalls.asyncBatchAnnotateImages = stubLongRunningCall(
         undefined,
@@ -476,11 +442,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
         client.asyncBatchAnnotateImages(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes asyncBatchAnnotateImages with LRO error', async () => {
@@ -492,7 +453,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.AsyncBatchAnnotateImagesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedError = new Error('expected');
       client.innerApiCalls.asyncBatchAnnotateImages = stubLongRunningCall(
         undefined,
@@ -501,11 +461,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       );
       const [operation] = await client.asyncBatchAnnotateImages(request);
       await assert.rejects(operation.promise(), expectedError);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes checkAsyncBatchAnnotateImagesProgress without error', async () => {
@@ -561,7 +516,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.AsyncBatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -570,11 +524,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const [operation] = await client.asyncBatchAnnotateFiles(request);
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes asyncBatchAnnotateFiles without error using callback', async () => {
@@ -586,7 +535,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.AsyncBatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -616,11 +564,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       >;
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
     });
 
     it('invokes asyncBatchAnnotateFiles with call error', async () => {
@@ -632,7 +575,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.AsyncBatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedError = new Error('expected');
       client.innerApiCalls.asyncBatchAnnotateFiles = stubLongRunningCall(
         undefined,
@@ -642,11 +584,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
         client.asyncBatchAnnotateFiles(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes asyncBatchAnnotateFiles with LRO error', async () => {
@@ -658,7 +595,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.AsyncBatchAnnotateFilesRequest()
       );
-      const expectedOptions = {otherArgs: {headers: {}}};
       const expectedError = new Error('expected');
       client.innerApiCalls.asyncBatchAnnotateFiles = stubLongRunningCall(
         undefined,
@@ -667,11 +603,6 @@ describe('v1p4beta1.ImageAnnotatorClient', () => {
       );
       const [operation] = await client.asyncBatchAnnotateFiles(request);
       await assert.rejects(operation.promise(), expectedError);
-      assert(
-        (client.innerApiCalls.asyncBatchAnnotateFiles as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
     });
 
     it('invokes checkAsyncBatchAnnotateFilesProgress without error', async () => {
diff --git a/test/gapic_product_search_v1.ts b/test/gapic_product_search_v1.ts
index ac4d6486..ae4ed49b 100644
--- a/test/gapic_product_search_v1.ts
+++ b/test/gapic_product_search_v1.ts
@@ -27,6 +27,21 @@ import {PassThrough} from 'stream';
 
 import {protobuf, LROperation, operationsProtos} from 'google-gax';
 
+// Dynamically loaded proto JSON is needed to get the type information
+// to fill in default values for request objects
+const root = protobuf.Root.fromJSON(
+  require('../protos/protos.json')
+).resolveAll();
+
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+function getTypeDefaultValue(typeName: string, fields: string[]) {
+  let type = root.lookupType(typeName) as protobuf.Type;
+  for (const field of fields.slice(0, -1)) {
+    type = type.fields[field]?.resolvedType as protobuf.Type;
+  }
+  return type.fields[fields[fields.length - 1]]?.defaultValue;
+}
+
 function generateSampleMessage<T extends object>(instance: T) {
   const filledObject = (
     instance.constructor as typeof protobuf.Message
@@ -254,26 +269,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.CreateProductSetRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.CreateProductSetRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.ProductSet()
       );
       client.innerApiCalls.createProductSet = stubSimpleCall(expectedResponse);
       const [response] = await client.createProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProductSet without error using callback', async () => {
@@ -285,15 +300,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.CreateProductSetRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.CreateProductSetRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.ProductSet()
       );
@@ -316,11 +328,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProductSet with error', async () => {
@@ -332,26 +347,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.CreateProductSetRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.CreateProductSetRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.createProductSet = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.createProductSet(request), expectedError);
-      assert(
-        (client.innerApiCalls.createProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProductSet with closed client', async () => {
@@ -363,7 +378,11 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.CreateProductSetRequest()
       );
-      request.parent = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.CreateProductSetRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.createProductSet(request), expectedError);
@@ -380,26 +399,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.GetProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.GetProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.ProductSet()
       );
       client.innerApiCalls.getProductSet = stubSimpleCall(expectedResponse);
       const [response] = await client.getProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProductSet without error using callback', async () => {
@@ -411,15 +430,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.GetProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.GetProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.ProductSet()
       );
@@ -442,11 +458,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProductSet with error', async () => {
@@ -458,26 +477,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.GetProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.GetProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.getProductSet = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.getProductSet(request), expectedError);
-      assert(
-        (client.innerApiCalls.getProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProductSet with closed client', async () => {
@@ -489,7 +508,11 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.GetProductSetRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.GetProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.getProductSet(request), expectedError);
@@ -506,27 +529,27 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.UpdateProductSetRequest()
       );
-      request.productSet = {};
-      request.productSet.name = '';
-      const expectedHeaderRequestParams = 'product_set.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.productSet ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.UpdateProductSetRequest',
+        ['productSet', 'name']
+      );
+      request.productSet.name = defaultValue1;
+      const expectedHeaderRequestParams = `product_set.name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.ProductSet()
       );
       client.innerApiCalls.updateProductSet = stubSimpleCall(expectedResponse);
       const [response] = await client.updateProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.updateProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProductSet without error using callback', async () => {
@@ -538,16 +561,13 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.UpdateProductSetRequest()
       );
-      request.productSet = {};
-      request.productSet.name = '';
-      const expectedHeaderRequestParams = 'product_set.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.productSet ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.UpdateProductSetRequest',
+        ['productSet', 'name']
+      );
+      request.productSet.name = defaultValue1;
+      const expectedHeaderRequestParams = `product_set.name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.ProductSet()
       );
@@ -570,11 +590,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.updateProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProductSet with error', async () => {
@@ -586,27 +609,27 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.UpdateProductSetRequest()
       );
-      request.productSet = {};
-      request.productSet.name = '';
-      const expectedHeaderRequestParams = 'product_set.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.productSet ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.UpdateProductSetRequest',
+        ['productSet', 'name']
+      );
+      request.productSet.name = defaultValue1;
+      const expectedHeaderRequestParams = `product_set.name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.updateProductSet = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.updateProductSet(request), expectedError);
-      assert(
-        (client.innerApiCalls.updateProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProductSet with closed client', async () => {
@@ -618,8 +641,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.UpdateProductSetRequest()
       );
-      request.productSet = {};
-      request.productSet.name = '';
+      request.productSet ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.UpdateProductSetRequest',
+        ['productSet', 'name']
+      );
+      request.productSet.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.updateProductSet(request), expectedError);
@@ -636,26 +663,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.DeleteProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.DeleteProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
       client.innerApiCalls.deleteProductSet = stubSimpleCall(expectedResponse);
       const [response] = await client.deleteProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProductSet without error using callback', async () => {
@@ -667,15 +694,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.DeleteProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.DeleteProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -698,11 +722,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProductSet with error', async () => {
@@ -714,26 +741,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.DeleteProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.DeleteProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.deleteProductSet = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.deleteProductSet(request), expectedError);
-      assert(
-        (client.innerApiCalls.deleteProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProductSet with closed client', async () => {
@@ -745,7 +772,11 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.DeleteProductSetRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.DeleteProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.deleteProductSet(request), expectedError);
@@ -762,26 +793,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.CreateProductRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.CreateProductRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.Product()
       );
       client.innerApiCalls.createProduct = stubSimpleCall(expectedResponse);
       const [response] = await client.createProduct(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProduct without error using callback', async () => {
@@ -793,15 +824,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.CreateProductRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.CreateProductRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.Product()
       );
@@ -824,11 +852,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProduct with error', async () => {
@@ -840,26 +871,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.CreateProductRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.CreateProductRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.createProduct = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.createProduct(request), expectedError);
-      assert(
-        (client.innerApiCalls.createProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProduct with closed client', async () => {
@@ -871,7 +902,11 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.CreateProductRequest()
       );
-      request.parent = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.CreateProductRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.createProduct(request), expectedError);
@@ -888,26 +923,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.GetProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.GetProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.Product()
       );
       client.innerApiCalls.getProduct = stubSimpleCall(expectedResponse);
       const [response] = await client.getProduct(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProduct without error using callback', async () => {
@@ -919,15 +954,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.GetProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.GetProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.Product()
       );
@@ -950,11 +982,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProduct with error', async () => {
@@ -966,26 +1001,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.GetProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.GetProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.getProduct = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.getProduct(request), expectedError);
-      assert(
-        (client.innerApiCalls.getProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProduct with closed client', async () => {
@@ -997,7 +1032,11 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.GetProductRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.GetProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.getProduct(request), expectedError);
@@ -1014,27 +1053,27 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.UpdateProductRequest()
       );
-      request.product = {};
-      request.product.name = '';
-      const expectedHeaderRequestParams = 'product.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.product ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.UpdateProductRequest',
+        ['product', 'name']
+      );
+      request.product.name = defaultValue1;
+      const expectedHeaderRequestParams = `product.name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.Product()
       );
       client.innerApiCalls.updateProduct = stubSimpleCall(expectedResponse);
       const [response] = await client.updateProduct(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.updateProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProduct without error using callback', async () => {
@@ -1046,16 +1085,13 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.UpdateProductRequest()
       );
-      request.product = {};
-      request.product.name = '';
-      const expectedHeaderRequestParams = 'product.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.product ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.UpdateProductRequest',
+        ['product', 'name']
+      );
+      request.product.name = defaultValue1;
+      const expectedHeaderRequestParams = `product.name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.Product()
       );
@@ -1078,11 +1114,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.updateProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProduct with error', async () => {
@@ -1094,27 +1133,27 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.UpdateProductRequest()
       );
-      request.product = {};
-      request.product.name = '';
-      const expectedHeaderRequestParams = 'product.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.product ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.UpdateProductRequest',
+        ['product', 'name']
+      );
+      request.product.name = defaultValue1;
+      const expectedHeaderRequestParams = `product.name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.updateProduct = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.updateProduct(request), expectedError);
-      assert(
-        (client.innerApiCalls.updateProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProduct with closed client', async () => {
@@ -1126,8 +1165,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.UpdateProductRequest()
       );
-      request.product = {};
-      request.product.name = '';
+      request.product ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.UpdateProductRequest',
+        ['product', 'name']
+      );
+      request.product.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.updateProduct(request), expectedError);
@@ -1144,26 +1187,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.DeleteProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.DeleteProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
       client.innerApiCalls.deleteProduct = stubSimpleCall(expectedResponse);
       const [response] = await client.deleteProduct(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProduct without error using callback', async () => {
@@ -1175,15 +1218,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.DeleteProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.DeleteProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1206,11 +1246,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProduct with error', async () => {
@@ -1222,26 +1265,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.DeleteProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.DeleteProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.deleteProduct = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.deleteProduct(request), expectedError);
-      assert(
-        (client.innerApiCalls.deleteProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProduct with closed client', async () => {
@@ -1253,7 +1296,11 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.DeleteProductRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.DeleteProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.deleteProduct(request), expectedError);
@@ -1270,15 +1317,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.CreateReferenceImageRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.CreateReferenceImageRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.ReferenceImage()
       );
@@ -1286,11 +1330,14 @@ describe('v1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.createReferenceImage(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createReferenceImage without error using callback', async () => {
@@ -1302,15 +1349,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.CreateReferenceImageRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.CreateReferenceImageRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.ReferenceImage()
       );
@@ -1333,11 +1377,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createReferenceImage with error', async () => {
@@ -1349,26 +1396,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.CreateReferenceImageRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.CreateReferenceImageRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.createReferenceImage = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.createReferenceImage(request), expectedError);
-      assert(
-        (client.innerApiCalls.createReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createReferenceImage with closed client', async () => {
@@ -1380,7 +1427,11 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.CreateReferenceImageRequest()
       );
-      request.parent = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.CreateReferenceImageRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.createReferenceImage(request), expectedError);
@@ -1397,15 +1448,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.DeleteReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.DeleteReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1413,11 +1461,14 @@ describe('v1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.deleteReferenceImage(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteReferenceImage without error using callback', async () => {
@@ -1429,15 +1480,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.DeleteReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.DeleteReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1460,11 +1508,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteReferenceImage with error', async () => {
@@ -1476,26 +1527,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.DeleteReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.DeleteReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.deleteReferenceImage = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.deleteReferenceImage(request), expectedError);
-      assert(
-        (client.innerApiCalls.deleteReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteReferenceImage with closed client', async () => {
@@ -1507,7 +1558,11 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.DeleteReferenceImageRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.DeleteReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.deleteReferenceImage(request), expectedError);
@@ -1524,26 +1579,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.GetReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.GetReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.ReferenceImage()
       );
       client.innerApiCalls.getReferenceImage = stubSimpleCall(expectedResponse);
       const [response] = await client.getReferenceImage(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getReferenceImage without error using callback', async () => {
@@ -1555,15 +1610,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.GetReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.GetReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1.ReferenceImage()
       );
@@ -1586,11 +1638,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getReferenceImage with error', async () => {
@@ -1602,26 +1657,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.GetReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.GetReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.getReferenceImage = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.getReferenceImage(request), expectedError);
-      assert(
-        (client.innerApiCalls.getReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getReferenceImage with closed client', async () => {
@@ -1633,7 +1688,11 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.GetReferenceImageRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.GetReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.getReferenceImage(request), expectedError);
@@ -1650,15 +1709,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.AddProductToProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.AddProductToProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1666,11 +1722,14 @@ describe('v1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.addProductToProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.addProductToProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes addProductToProductSet without error using callback', async () => {
@@ -1682,15 +1741,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.AddProductToProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.AddProductToProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1713,11 +1769,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.addProductToProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes addProductToProductSet with error', async () => {
@@ -1729,15 +1788,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.AddProductToProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.AddProductToProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.addProductToProductSet = stubSimpleCall(
         undefined,
@@ -1747,11 +1803,14 @@ describe('v1.ProductSearchClient', () => {
         client.addProductToProductSet(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.addProductToProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes addProductToProductSet with closed client', async () => {
@@ -1763,7 +1822,11 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.AddProductToProductSetRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.AddProductToProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(
@@ -1783,15 +1846,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.RemoveProductFromProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.RemoveProductFromProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1799,11 +1859,14 @@ describe('v1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.removeProductFromProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.removeProductFromProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes removeProductFromProductSet without error using callback', async () => {
@@ -1815,15 +1878,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.RemoveProductFromProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.RemoveProductFromProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1846,11 +1906,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.removeProductFromProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes removeProductFromProductSet with error', async () => {
@@ -1862,15 +1925,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.RemoveProductFromProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.RemoveProductFromProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.removeProductFromProductSet = stubSimpleCall(
         undefined,
@@ -1880,11 +1940,14 @@ describe('v1.ProductSearchClient', () => {
         client.removeProductFromProductSet(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.removeProductFromProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes removeProductFromProductSet with closed client', async () => {
@@ -1896,7 +1959,11 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.RemoveProductFromProductSetRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.RemoveProductFromProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(
@@ -1916,15 +1983,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ImportProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ImportProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -1933,11 +1997,14 @@ describe('v1.ProductSearchClient', () => {
       const [operation] = await client.importProductSets(request);
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.importProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes importProductSets without error using callback', async () => {
@@ -1949,15 +2016,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ImportProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ImportProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -1987,11 +2051,14 @@ describe('v1.ProductSearchClient', () => {
       >;
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.importProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes importProductSets with call error', async () => {
@@ -2003,26 +2070,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ImportProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ImportProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.importProductSets = stubLongRunningCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.importProductSets(request), expectedError);
-      assert(
-        (client.innerApiCalls.importProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes importProductSets with LRO error', async () => {
@@ -2034,15 +2101,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ImportProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ImportProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.importProductSets = stubLongRunningCall(
         undefined,
@@ -2051,11 +2115,14 @@ describe('v1.ProductSearchClient', () => {
       );
       const [operation] = await client.importProductSets(request);
       await assert.rejects(operation.promise(), expectedError);
-      assert(
-        (client.innerApiCalls.importProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes checkImportProductSetsProgress without error', async () => {
@@ -2110,15 +2177,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.PurgeProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.PurgeProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -2127,11 +2191,14 @@ describe('v1.ProductSearchClient', () => {
       const [operation] = await client.purgeProducts(request);
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.purgeProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes purgeProducts without error using callback', async () => {
@@ -2143,15 +2210,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.PurgeProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.PurgeProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -2181,11 +2245,14 @@ describe('v1.ProductSearchClient', () => {
       >;
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.purgeProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes purgeProducts with call error', async () => {
@@ -2197,26 +2264,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.PurgeProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.PurgeProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.purgeProducts = stubLongRunningCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.purgeProducts(request), expectedError);
-      assert(
-        (client.innerApiCalls.purgeProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes purgeProducts with LRO error', async () => {
@@ -2228,15 +2295,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.PurgeProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.PurgeProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.purgeProducts = stubLongRunningCall(
         undefined,
@@ -2245,11 +2309,14 @@ describe('v1.ProductSearchClient', () => {
       );
       const [operation] = await client.purgeProducts(request);
       await assert.rejects(operation.promise(), expectedError);
-      assert(
-        (client.innerApiCalls.purgeProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes checkPurgeProductsProgress without error', async () => {
@@ -2304,15 +2371,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(new protos.google.cloud.vision.v1.ProductSet()),
         generateSampleMessage(new protos.google.cloud.vision.v1.ProductSet()),
@@ -2321,11 +2385,14 @@ describe('v1.ProductSearchClient', () => {
       client.innerApiCalls.listProductSets = stubSimpleCall(expectedResponse);
       const [response] = await client.listProductSets(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductSets without error using callback', async () => {
@@ -2337,15 +2404,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(new protos.google.cloud.vision.v1.ProductSet()),
         generateSampleMessage(new protos.google.cloud.vision.v1.ProductSet()),
@@ -2370,11 +2434,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductSets with error', async () => {
@@ -2386,26 +2453,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.listProductSets = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.listProductSets(request), expectedError);
-      assert(
-        (client.innerApiCalls.listProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductSetsStream without error', async () => {
@@ -2417,8 +2484,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(new protos.google.cloud.vision.v1.ProductSet()),
         generateSampleMessage(new protos.google.cloud.vision.v1.ProductSet()),
@@ -2449,11 +2520,12 @@ describe('v1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProductSets, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProductSets.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProductSets.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2466,8 +2538,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProductSets.createStream =
         stubPageStreamingCall(undefined, expectedError);
@@ -2493,11 +2569,12 @@ describe('v1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProductSets, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProductSets.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProductSets.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2510,8 +2587,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(new protos.google.cloud.vision.v1.ProductSet()),
         generateSampleMessage(new protos.google.cloud.vision.v1.ProductSet()),
@@ -2531,11 +2612,12 @@ describe('v1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProductSets.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProductSets.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2548,8 +2630,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProductSets.asyncIterate =
         stubAsyncIterationCall(undefined, expectedError);
@@ -2566,11 +2652,12 @@ describe('v1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProductSets.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProductSets.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
   });
@@ -2585,15 +2672,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
@@ -2602,11 +2686,14 @@ describe('v1.ProductSearchClient', () => {
       client.innerApiCalls.listProducts = stubSimpleCall(expectedResponse);
       const [response] = await client.listProducts(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProducts without error using callback', async () => {
@@ -2618,15 +2705,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
@@ -2651,11 +2735,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProducts with error', async () => {
@@ -2667,26 +2754,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.listProducts = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.listProducts(request), expectedError);
-      assert(
-        (client.innerApiCalls.listProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductsStream without error', async () => {
@@ -2698,8 +2785,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
@@ -2727,11 +2818,12 @@ describe('v1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProducts, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProducts.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProducts.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2744,8 +2836,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProducts.createStream = stubPageStreamingCall(
         undefined,
@@ -2770,11 +2866,12 @@ describe('v1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProducts, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProducts.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProducts.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2787,8 +2884,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
@@ -2808,11 +2909,12 @@ describe('v1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProducts.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProducts.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2825,8 +2927,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProducts.asyncIterate =
         stubAsyncIterationCall(undefined, expectedError);
@@ -2843,11 +2949,12 @@ describe('v1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProducts.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProducts.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
   });
@@ -2862,15 +2969,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1.ReferenceImage()
@@ -2886,11 +2990,14 @@ describe('v1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.listReferenceImages(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listReferenceImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listReferenceImages without error using callback', async () => {
@@ -2902,15 +3009,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1.ReferenceImage()
@@ -2941,11 +3045,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listReferenceImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listReferenceImages with error', async () => {
@@ -2957,26 +3064,26 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.listReferenceImages = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.listReferenceImages(request), expectedError);
-      assert(
-        (client.innerApiCalls.listReferenceImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listReferenceImagesStream without error', async () => {
@@ -2988,8 +3095,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1.ReferenceImage()
@@ -3026,11 +3137,12 @@ describe('v1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listReferenceImages, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listReferenceImages.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listReferenceImages.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3043,8 +3155,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listReferenceImages.createStream =
         stubPageStreamingCall(undefined, expectedError);
@@ -3070,11 +3186,12 @@ describe('v1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listReferenceImages, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listReferenceImages.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listReferenceImages.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3087,8 +3204,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1.ReferenceImage()
@@ -3114,11 +3235,12 @@ describe('v1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listReferenceImages.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listReferenceImages.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3131,8 +3253,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listReferenceImages.asyncIterate =
         stubAsyncIterationCall(undefined, expectedError);
@@ -3149,11 +3275,12 @@ describe('v1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listReferenceImages.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listReferenceImages.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
   });
@@ -3168,15 +3295,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
@@ -3186,11 +3310,14 @@ describe('v1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.listProductsInProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProductsInProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductsInProductSet without error using callback', async () => {
@@ -3202,15 +3329,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
@@ -3235,11 +3359,14 @@ describe('v1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProductsInProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductsInProductSet with error', async () => {
@@ -3251,15 +3378,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.listProductsInProductSet = stubSimpleCall(
         undefined,
@@ -3269,11 +3393,14 @@ describe('v1.ProductSearchClient', () => {
         client.listProductsInProductSet(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.listProductsInProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductsInProductSetStream without error', async () => {
@@ -3285,8 +3412,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
@@ -3317,12 +3448,15 @@ describe('v1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProductsInProductSet, request)
       );
-      assert.strictEqual(
+      assert(
         (
           client.descriptors.page.listProductsInProductSet
             .createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+        )
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3335,8 +3469,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProductsInProductSet.createStream =
         stubPageStreamingCall(undefined, expectedError);
@@ -3362,12 +3500,15 @@ describe('v1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProductsInProductSet, request)
       );
-      assert.strictEqual(
+      assert(
         (
           client.descriptors.page.listProductsInProductSet
             .createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+        )
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3380,8 +3521,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
         generateSampleMessage(new protos.google.cloud.vision.v1.Product()),
@@ -3402,12 +3547,15 @@ describe('v1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
+      assert(
         (
           client.descriptors.page.listProductsInProductSet
             .asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+        )
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3420,8 +3568,12 @@ describe('v1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProductsInProductSet.asyncIterate =
         stubAsyncIterationCall(undefined, expectedError);
@@ -3439,12 +3591,15 @@ describe('v1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
+      assert(
         (
           client.descriptors.page.listProductsInProductSet
             .asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+        )
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
   });
diff --git a/test/gapic_product_search_v1p3beta1.ts b/test/gapic_product_search_v1p3beta1.ts
index adad0827..32845326 100644
--- a/test/gapic_product_search_v1p3beta1.ts
+++ b/test/gapic_product_search_v1p3beta1.ts
@@ -27,6 +27,21 @@ import {PassThrough} from 'stream';
 
 import {protobuf, LROperation, operationsProtos} from 'google-gax';
 
+// Dynamically loaded proto JSON is needed to get the type information
+// to fill in default values for request objects
+const root = protobuf.Root.fromJSON(
+  require('../protos/protos.json')
+).resolveAll();
+
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+function getTypeDefaultValue(typeName: string, fields: string[]) {
+  let type = root.lookupType(typeName) as protobuf.Type;
+  for (const field of fields.slice(0, -1)) {
+    type = type.fields[field]?.resolvedType as protobuf.Type;
+  }
+  return type.fields[fields[fields.length - 1]]?.defaultValue;
+}
+
 function generateSampleMessage<T extends object>(instance: T) {
   const filledObject = (
     instance.constructor as typeof protobuf.Message
@@ -254,26 +269,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.CreateProductSetRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.CreateProductSetRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ProductSet()
       );
       client.innerApiCalls.createProductSet = stubSimpleCall(expectedResponse);
       const [response] = await client.createProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProductSet without error using callback', async () => {
@@ -285,15 +300,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.CreateProductSetRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.CreateProductSetRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ProductSet()
       );
@@ -316,11 +328,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProductSet with error', async () => {
@@ -332,26 +347,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.CreateProductSetRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.CreateProductSetRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.createProductSet = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.createProductSet(request), expectedError);
-      assert(
-        (client.innerApiCalls.createProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProductSet with closed client', async () => {
@@ -363,7 +378,11 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.CreateProductSetRequest()
       );
-      request.parent = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.CreateProductSetRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.createProductSet(request), expectedError);
@@ -380,26 +399,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.GetProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.GetProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ProductSet()
       );
       client.innerApiCalls.getProductSet = stubSimpleCall(expectedResponse);
       const [response] = await client.getProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProductSet without error using callback', async () => {
@@ -411,15 +430,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.GetProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.GetProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ProductSet()
       );
@@ -442,11 +458,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProductSet with error', async () => {
@@ -458,26 +477,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.GetProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.GetProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.getProductSet = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.getProductSet(request), expectedError);
-      assert(
-        (client.innerApiCalls.getProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProductSet with closed client', async () => {
@@ -489,7 +508,11 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.GetProductSetRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.GetProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.getProductSet(request), expectedError);
@@ -506,27 +529,27 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.UpdateProductSetRequest()
       );
-      request.productSet = {};
-      request.productSet.name = '';
-      const expectedHeaderRequestParams = 'product_set.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.productSet ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.UpdateProductSetRequest',
+        ['productSet', 'name']
+      );
+      request.productSet.name = defaultValue1;
+      const expectedHeaderRequestParams = `product_set.name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ProductSet()
       );
       client.innerApiCalls.updateProductSet = stubSimpleCall(expectedResponse);
       const [response] = await client.updateProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.updateProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProductSet without error using callback', async () => {
@@ -538,16 +561,13 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.UpdateProductSetRequest()
       );
-      request.productSet = {};
-      request.productSet.name = '';
-      const expectedHeaderRequestParams = 'product_set.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.productSet ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.UpdateProductSetRequest',
+        ['productSet', 'name']
+      );
+      request.productSet.name = defaultValue1;
+      const expectedHeaderRequestParams = `product_set.name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ProductSet()
       );
@@ -570,11 +590,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.updateProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProductSet with error', async () => {
@@ -586,27 +609,27 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.UpdateProductSetRequest()
       );
-      request.productSet = {};
-      request.productSet.name = '';
-      const expectedHeaderRequestParams = 'product_set.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.productSet ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.UpdateProductSetRequest',
+        ['productSet', 'name']
+      );
+      request.productSet.name = defaultValue1;
+      const expectedHeaderRequestParams = `product_set.name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.updateProductSet = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.updateProductSet(request), expectedError);
-      assert(
-        (client.innerApiCalls.updateProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProductSet with closed client', async () => {
@@ -618,8 +641,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.UpdateProductSetRequest()
       );
-      request.productSet = {};
-      request.productSet.name = '';
+      request.productSet ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.UpdateProductSetRequest',
+        ['productSet', 'name']
+      );
+      request.productSet.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.updateProductSet(request), expectedError);
@@ -636,26 +663,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.DeleteProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.DeleteProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
       client.innerApiCalls.deleteProductSet = stubSimpleCall(expectedResponse);
       const [response] = await client.deleteProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProductSet without error using callback', async () => {
@@ -667,15 +694,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.DeleteProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.DeleteProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -698,11 +722,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProductSet with error', async () => {
@@ -714,26 +741,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.DeleteProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.DeleteProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.deleteProductSet = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.deleteProductSet(request), expectedError);
-      assert(
-        (client.innerApiCalls.deleteProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProductSet with closed client', async () => {
@@ -745,7 +772,11 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.DeleteProductSetRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.DeleteProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.deleteProductSet(request), expectedError);
@@ -762,26 +793,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.CreateProductRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.CreateProductRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.Product()
       );
       client.innerApiCalls.createProduct = stubSimpleCall(expectedResponse);
       const [response] = await client.createProduct(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProduct without error using callback', async () => {
@@ -793,15 +824,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.CreateProductRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.CreateProductRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.Product()
       );
@@ -824,11 +852,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProduct with error', async () => {
@@ -840,26 +871,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.CreateProductRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.CreateProductRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.createProduct = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.createProduct(request), expectedError);
-      assert(
-        (client.innerApiCalls.createProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProduct with closed client', async () => {
@@ -871,7 +902,11 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.CreateProductRequest()
       );
-      request.parent = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.CreateProductRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.createProduct(request), expectedError);
@@ -888,26 +923,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.GetProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.GetProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.Product()
       );
       client.innerApiCalls.getProduct = stubSimpleCall(expectedResponse);
       const [response] = await client.getProduct(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProduct without error using callback', async () => {
@@ -919,15 +954,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.GetProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.GetProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.Product()
       );
@@ -950,11 +982,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProduct with error', async () => {
@@ -966,26 +1001,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.GetProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.GetProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.getProduct = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.getProduct(request), expectedError);
-      assert(
-        (client.innerApiCalls.getProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProduct with closed client', async () => {
@@ -997,7 +1032,11 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.GetProductRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.GetProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.getProduct(request), expectedError);
@@ -1014,27 +1053,27 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.UpdateProductRequest()
       );
-      request.product = {};
-      request.product.name = '';
-      const expectedHeaderRequestParams = 'product.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.product ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.UpdateProductRequest',
+        ['product', 'name']
+      );
+      request.product.name = defaultValue1;
+      const expectedHeaderRequestParams = `product.name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.Product()
       );
       client.innerApiCalls.updateProduct = stubSimpleCall(expectedResponse);
       const [response] = await client.updateProduct(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.updateProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProduct without error using callback', async () => {
@@ -1046,16 +1085,13 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.UpdateProductRequest()
       );
-      request.product = {};
-      request.product.name = '';
-      const expectedHeaderRequestParams = 'product.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.product ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.UpdateProductRequest',
+        ['product', 'name']
+      );
+      request.product.name = defaultValue1;
+      const expectedHeaderRequestParams = `product.name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.Product()
       );
@@ -1078,11 +1114,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.updateProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProduct with error', async () => {
@@ -1094,27 +1133,27 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.UpdateProductRequest()
       );
-      request.product = {};
-      request.product.name = '';
-      const expectedHeaderRequestParams = 'product.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.product ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.UpdateProductRequest',
+        ['product', 'name']
+      );
+      request.product.name = defaultValue1;
+      const expectedHeaderRequestParams = `product.name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.updateProduct = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.updateProduct(request), expectedError);
-      assert(
-        (client.innerApiCalls.updateProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProduct with closed client', async () => {
@@ -1126,8 +1165,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.UpdateProductRequest()
       );
-      request.product = {};
-      request.product.name = '';
+      request.product ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.UpdateProductRequest',
+        ['product', 'name']
+      );
+      request.product.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.updateProduct(request), expectedError);
@@ -1144,26 +1187,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.DeleteProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.DeleteProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
       client.innerApiCalls.deleteProduct = stubSimpleCall(expectedResponse);
       const [response] = await client.deleteProduct(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProduct without error using callback', async () => {
@@ -1175,15 +1218,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.DeleteProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.DeleteProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1206,11 +1246,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProduct with error', async () => {
@@ -1222,26 +1265,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.DeleteProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.DeleteProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.deleteProduct = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.deleteProduct(request), expectedError);
-      assert(
-        (client.innerApiCalls.deleteProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProduct with closed client', async () => {
@@ -1253,7 +1296,11 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.DeleteProductRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.DeleteProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.deleteProduct(request), expectedError);
@@ -1270,15 +1317,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.CreateReferenceImageRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.CreateReferenceImageRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ReferenceImage()
       );
@@ -1286,11 +1330,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.createReferenceImage(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createReferenceImage without error using callback', async () => {
@@ -1302,15 +1349,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.CreateReferenceImageRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.CreateReferenceImageRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ReferenceImage()
       );
@@ -1333,11 +1377,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createReferenceImage with error', async () => {
@@ -1349,26 +1396,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.CreateReferenceImageRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.CreateReferenceImageRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.createReferenceImage = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.createReferenceImage(request), expectedError);
-      assert(
-        (client.innerApiCalls.createReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createReferenceImage with closed client', async () => {
@@ -1380,7 +1427,11 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.CreateReferenceImageRequest()
       );
-      request.parent = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.CreateReferenceImageRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.createReferenceImage(request), expectedError);
@@ -1397,15 +1448,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.DeleteReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.DeleteReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1413,11 +1461,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.deleteReferenceImage(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteReferenceImage without error using callback', async () => {
@@ -1429,15 +1480,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.DeleteReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.DeleteReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1460,11 +1508,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteReferenceImage with error', async () => {
@@ -1476,26 +1527,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.DeleteReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.DeleteReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.deleteReferenceImage = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.deleteReferenceImage(request), expectedError);
-      assert(
-        (client.innerApiCalls.deleteReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteReferenceImage with closed client', async () => {
@@ -1507,7 +1558,11 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.DeleteReferenceImageRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.DeleteReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.deleteReferenceImage(request), expectedError);
@@ -1524,26 +1579,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.GetReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.GetReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ReferenceImage()
       );
       client.innerApiCalls.getReferenceImage = stubSimpleCall(expectedResponse);
       const [response] = await client.getReferenceImage(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getReferenceImage without error using callback', async () => {
@@ -1555,15 +1610,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.GetReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.GetReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ReferenceImage()
       );
@@ -1586,11 +1638,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getReferenceImage with error', async () => {
@@ -1602,26 +1657,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.GetReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.GetReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.getReferenceImage = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.getReferenceImage(request), expectedError);
-      assert(
-        (client.innerApiCalls.getReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getReferenceImage with closed client', async () => {
@@ -1633,7 +1688,11 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.GetReferenceImageRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.GetReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.getReferenceImage(request), expectedError);
@@ -1650,15 +1709,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.AddProductToProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.AddProductToProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1666,11 +1722,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.addProductToProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.addProductToProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes addProductToProductSet without error using callback', async () => {
@@ -1682,15 +1741,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.AddProductToProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.AddProductToProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1713,11 +1769,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.addProductToProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes addProductToProductSet with error', async () => {
@@ -1729,15 +1788,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.AddProductToProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.AddProductToProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.addProductToProductSet = stubSimpleCall(
         undefined,
@@ -1747,11 +1803,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
         client.addProductToProductSet(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.addProductToProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes addProductToProductSet with closed client', async () => {
@@ -1763,7 +1822,11 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.AddProductToProductSetRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.AddProductToProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(
@@ -1783,15 +1846,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.RemoveProductFromProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.RemoveProductFromProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1799,11 +1859,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.removeProductFromProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.removeProductFromProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes removeProductFromProductSet without error using callback', async () => {
@@ -1815,15 +1878,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.RemoveProductFromProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.RemoveProductFromProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1846,11 +1906,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.removeProductFromProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes removeProductFromProductSet with error', async () => {
@@ -1862,15 +1925,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.RemoveProductFromProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.RemoveProductFromProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.removeProductFromProductSet = stubSimpleCall(
         undefined,
@@ -1880,11 +1940,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
         client.removeProductFromProductSet(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.removeProductFromProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes removeProductFromProductSet with closed client', async () => {
@@ -1896,7 +1959,11 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.RemoveProductFromProductSetRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.RemoveProductFromProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(
@@ -1916,15 +1983,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ImportProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ImportProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -1933,11 +1997,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const [operation] = await client.importProductSets(request);
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.importProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes importProductSets without error using callback', async () => {
@@ -1949,15 +2016,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ImportProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ImportProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -1987,11 +2051,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       >;
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.importProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes importProductSets with call error', async () => {
@@ -2003,26 +2070,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ImportProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ImportProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.importProductSets = stubLongRunningCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.importProductSets(request), expectedError);
-      assert(
-        (client.innerApiCalls.importProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes importProductSets with LRO error', async () => {
@@ -2034,15 +2101,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ImportProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ImportProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.importProductSets = stubLongRunningCall(
         undefined,
@@ -2051,11 +2115,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       );
       const [operation] = await client.importProductSets(request);
       await assert.rejects(operation.promise(), expectedError);
-      assert(
-        (client.innerApiCalls.importProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes checkImportProductSetsProgress without error', async () => {
@@ -2110,15 +2177,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.ProductSet()
@@ -2133,11 +2197,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       client.innerApiCalls.listProductSets = stubSimpleCall(expectedResponse);
       const [response] = await client.listProductSets(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductSets without error using callback', async () => {
@@ -2149,15 +2216,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.ProductSet()
@@ -2188,11 +2252,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductSets with error', async () => {
@@ -2204,26 +2271,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.listProductSets = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.listProductSets(request), expectedError);
-      assert(
-        (client.innerApiCalls.listProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductSetsStream without error', async () => {
@@ -2235,8 +2302,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.ProductSet()
@@ -2273,11 +2344,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProductSets, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProductSets.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProductSets.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2290,8 +2362,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProductSets.createStream =
         stubPageStreamingCall(undefined, expectedError);
@@ -2317,11 +2393,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProductSets, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProductSets.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProductSets.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2334,8 +2411,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.ProductSet()
@@ -2361,11 +2442,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProductSets.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProductSets.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2378,8 +2460,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProductSets.asyncIterate =
         stubAsyncIterationCall(undefined, expectedError);
@@ -2397,11 +2483,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProductSets.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProductSets.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
   });
@@ -2416,15 +2503,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.Product()
@@ -2439,11 +2523,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       client.innerApiCalls.listProducts = stubSimpleCall(expectedResponse);
       const [response] = await client.listProducts(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProducts without error using callback', async () => {
@@ -2455,15 +2542,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.Product()
@@ -2494,11 +2578,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProducts with error', async () => {
@@ -2510,26 +2597,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.listProducts = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.listProducts(request), expectedError);
-      assert(
-        (client.innerApiCalls.listProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductsStream without error', async () => {
@@ -2541,8 +2628,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.Product()
@@ -2579,11 +2670,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProducts, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProducts.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProducts.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2596,8 +2688,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProducts.createStream = stubPageStreamingCall(
         undefined,
@@ -2625,11 +2721,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProducts, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProducts.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProducts.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2642,8 +2739,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.Product()
@@ -2669,11 +2770,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProducts.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProducts.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2686,8 +2788,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProducts.asyncIterate =
         stubAsyncIterationCall(undefined, expectedError);
@@ -2704,11 +2810,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProducts.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProducts.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
   });
@@ -2723,15 +2830,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.ReferenceImage()
@@ -2747,11 +2851,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.listReferenceImages(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listReferenceImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listReferenceImages without error using callback', async () => {
@@ -2763,15 +2870,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.ReferenceImage()
@@ -2804,11 +2908,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listReferenceImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listReferenceImages with error', async () => {
@@ -2820,26 +2927,26 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.listReferenceImages = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.listReferenceImages(request), expectedError);
-      assert(
-        (client.innerApiCalls.listReferenceImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listReferenceImagesStream without error', async () => {
@@ -2851,8 +2958,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.ReferenceImage()
@@ -2890,11 +3001,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listReferenceImages, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listReferenceImages.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listReferenceImages.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2907,8 +3019,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listReferenceImages.createStream =
         stubPageStreamingCall(undefined, expectedError);
@@ -2935,11 +3051,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listReferenceImages, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listReferenceImages.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listReferenceImages.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2952,8 +3069,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.ReferenceImage()
@@ -2980,11 +3101,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listReferenceImages.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listReferenceImages.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2997,8 +3119,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listReferenceImages.asyncIterate =
         stubAsyncIterationCall(undefined, expectedError);
@@ -3016,11 +3142,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listReferenceImages.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listReferenceImages.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
   });
@@ -3035,15 +3162,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.Product()
@@ -3059,11 +3183,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.listProductsInProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProductsInProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductsInProductSet without error using callback', async () => {
@@ -3075,15 +3202,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.Product()
@@ -3114,11 +3238,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProductsInProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductsInProductSet with error', async () => {
@@ -3130,15 +3257,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.listProductsInProductSet = stubSimpleCall(
         undefined,
@@ -3148,11 +3272,14 @@ describe('v1p3beta1.ProductSearchClient', () => {
         client.listProductsInProductSet(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.listProductsInProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductsInProductSetStream without error', async () => {
@@ -3164,8 +3291,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.Product()
@@ -3205,12 +3336,15 @@ describe('v1p3beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProductsInProductSet, request)
       );
-      assert.strictEqual(
+      assert(
         (
           client.descriptors.page.listProductsInProductSet
             .createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+        )
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3223,8 +3357,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProductsInProductSet.createStream =
         stubPageStreamingCall(undefined, expectedError);
@@ -3253,12 +3391,15 @@ describe('v1p3beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProductsInProductSet, request)
       );
-      assert.strictEqual(
+      assert(
         (
           client.descriptors.page.listProductsInProductSet
             .createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+        )
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3271,8 +3412,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p3beta1.Product()
@@ -3299,12 +3444,15 @@ describe('v1p3beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
+      assert(
         (
           client.descriptors.page.listProductsInProductSet
             .asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+        )
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3317,8 +3465,12 @@ describe('v1p3beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p3beta1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p3beta1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProductsInProductSet.asyncIterate =
         stubAsyncIterationCall(undefined, expectedError);
@@ -3336,12 +3488,15 @@ describe('v1p3beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
+      assert(
         (
           client.descriptors.page.listProductsInProductSet
             .asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+        )
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
   });
diff --git a/test/gapic_product_search_v1p4beta1.ts b/test/gapic_product_search_v1p4beta1.ts
index 538ec6e0..6baa71c8 100644
--- a/test/gapic_product_search_v1p4beta1.ts
+++ b/test/gapic_product_search_v1p4beta1.ts
@@ -27,6 +27,21 @@ import {PassThrough} from 'stream';
 
 import {protobuf, LROperation, operationsProtos} from 'google-gax';
 
+// Dynamically loaded proto JSON is needed to get the type information
+// to fill in default values for request objects
+const root = protobuf.Root.fromJSON(
+  require('../protos/protos.json')
+).resolveAll();
+
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+function getTypeDefaultValue(typeName: string, fields: string[]) {
+  let type = root.lookupType(typeName) as protobuf.Type;
+  for (const field of fields.slice(0, -1)) {
+    type = type.fields[field]?.resolvedType as protobuf.Type;
+  }
+  return type.fields[fields[fields.length - 1]]?.defaultValue;
+}
+
 function generateSampleMessage<T extends object>(instance: T) {
   const filledObject = (
     instance.constructor as typeof protobuf.Message
@@ -254,26 +269,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.CreateProductSetRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.CreateProductSetRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ProductSet()
       );
       client.innerApiCalls.createProductSet = stubSimpleCall(expectedResponse);
       const [response] = await client.createProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProductSet without error using callback', async () => {
@@ -285,15 +300,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.CreateProductSetRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.CreateProductSetRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ProductSet()
       );
@@ -316,11 +328,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProductSet with error', async () => {
@@ -332,26 +347,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.CreateProductSetRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.CreateProductSetRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.createProductSet = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.createProductSet(request), expectedError);
-      assert(
-        (client.innerApiCalls.createProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProductSet with closed client', async () => {
@@ -363,7 +378,11 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.CreateProductSetRequest()
       );
-      request.parent = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.CreateProductSetRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.createProductSet(request), expectedError);
@@ -380,26 +399,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.GetProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.GetProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ProductSet()
       );
       client.innerApiCalls.getProductSet = stubSimpleCall(expectedResponse);
       const [response] = await client.getProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProductSet without error using callback', async () => {
@@ -411,15 +430,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.GetProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.GetProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ProductSet()
       );
@@ -442,11 +458,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProductSet with error', async () => {
@@ -458,26 +477,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.GetProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.GetProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.getProductSet = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.getProductSet(request), expectedError);
-      assert(
-        (client.innerApiCalls.getProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProductSet with closed client', async () => {
@@ -489,7 +508,11 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.GetProductSetRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.GetProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.getProductSet(request), expectedError);
@@ -506,27 +529,27 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.UpdateProductSetRequest()
       );
-      request.productSet = {};
-      request.productSet.name = '';
-      const expectedHeaderRequestParams = 'product_set.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.productSet ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.UpdateProductSetRequest',
+        ['productSet', 'name']
+      );
+      request.productSet.name = defaultValue1;
+      const expectedHeaderRequestParams = `product_set.name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ProductSet()
       );
       client.innerApiCalls.updateProductSet = stubSimpleCall(expectedResponse);
       const [response] = await client.updateProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.updateProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProductSet without error using callback', async () => {
@@ -538,16 +561,13 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.UpdateProductSetRequest()
       );
-      request.productSet = {};
-      request.productSet.name = '';
-      const expectedHeaderRequestParams = 'product_set.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.productSet ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.UpdateProductSetRequest',
+        ['productSet', 'name']
+      );
+      request.productSet.name = defaultValue1;
+      const expectedHeaderRequestParams = `product_set.name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ProductSet()
       );
@@ -570,11 +590,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.updateProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProductSet with error', async () => {
@@ -586,27 +609,27 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.UpdateProductSetRequest()
       );
-      request.productSet = {};
-      request.productSet.name = '';
-      const expectedHeaderRequestParams = 'product_set.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.productSet ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.UpdateProductSetRequest',
+        ['productSet', 'name']
+      );
+      request.productSet.name = defaultValue1;
+      const expectedHeaderRequestParams = `product_set.name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.updateProductSet = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.updateProductSet(request), expectedError);
-      assert(
-        (client.innerApiCalls.updateProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProductSet with closed client', async () => {
@@ -618,8 +641,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.UpdateProductSetRequest()
       );
-      request.productSet = {};
-      request.productSet.name = '';
+      request.productSet ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.UpdateProductSetRequest',
+        ['productSet', 'name']
+      );
+      request.productSet.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.updateProductSet(request), expectedError);
@@ -636,26 +663,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.DeleteProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.DeleteProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
       client.innerApiCalls.deleteProductSet = stubSimpleCall(expectedResponse);
       const [response] = await client.deleteProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProductSet without error using callback', async () => {
@@ -667,15 +694,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.DeleteProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.DeleteProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -698,11 +722,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProductSet with error', async () => {
@@ -714,26 +741,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.DeleteProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.DeleteProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.deleteProductSet = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.deleteProductSet(request), expectedError);
-      assert(
-        (client.innerApiCalls.deleteProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProductSet with closed client', async () => {
@@ -745,7 +772,11 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.DeleteProductSetRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.DeleteProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.deleteProductSet(request), expectedError);
@@ -762,26 +793,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.CreateProductRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.CreateProductRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.Product()
       );
       client.innerApiCalls.createProduct = stubSimpleCall(expectedResponse);
       const [response] = await client.createProduct(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProduct without error using callback', async () => {
@@ -793,15 +824,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.CreateProductRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.CreateProductRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.Product()
       );
@@ -824,11 +852,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProduct with error', async () => {
@@ -840,26 +871,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.CreateProductRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.CreateProductRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.createProduct = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.createProduct(request), expectedError);
-      assert(
-        (client.innerApiCalls.createProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createProduct with closed client', async () => {
@@ -871,7 +902,11 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.CreateProductRequest()
       );
-      request.parent = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.CreateProductRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.createProduct(request), expectedError);
@@ -888,26 +923,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.GetProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.GetProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.Product()
       );
       client.innerApiCalls.getProduct = stubSimpleCall(expectedResponse);
       const [response] = await client.getProduct(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProduct without error using callback', async () => {
@@ -919,15 +954,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.GetProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.GetProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.Product()
       );
@@ -950,11 +982,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProduct with error', async () => {
@@ -966,26 +1001,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.GetProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.GetProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.getProduct = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.getProduct(request), expectedError);
-      assert(
-        (client.innerApiCalls.getProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getProduct with closed client', async () => {
@@ -997,7 +1032,11 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.GetProductRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.GetProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.getProduct(request), expectedError);
@@ -1014,27 +1053,27 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.UpdateProductRequest()
       );
-      request.product = {};
-      request.product.name = '';
-      const expectedHeaderRequestParams = 'product.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.product ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.UpdateProductRequest',
+        ['product', 'name']
+      );
+      request.product.name = defaultValue1;
+      const expectedHeaderRequestParams = `product.name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.Product()
       );
       client.innerApiCalls.updateProduct = stubSimpleCall(expectedResponse);
       const [response] = await client.updateProduct(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.updateProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProduct without error using callback', async () => {
@@ -1046,16 +1085,13 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.UpdateProductRequest()
       );
-      request.product = {};
-      request.product.name = '';
-      const expectedHeaderRequestParams = 'product.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.product ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.UpdateProductRequest',
+        ['product', 'name']
+      );
+      request.product.name = defaultValue1;
+      const expectedHeaderRequestParams = `product.name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.Product()
       );
@@ -1078,11 +1114,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.updateProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProduct with error', async () => {
@@ -1094,27 +1133,27 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.UpdateProductRequest()
       );
-      request.product = {};
-      request.product.name = '';
-      const expectedHeaderRequestParams = 'product.name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      request.product ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.UpdateProductRequest',
+        ['product', 'name']
+      );
+      request.product.name = defaultValue1;
+      const expectedHeaderRequestParams = `product.name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.updateProduct = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.updateProduct(request), expectedError);
-      assert(
-        (client.innerApiCalls.updateProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.updateProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes updateProduct with closed client', async () => {
@@ -1126,8 +1165,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.UpdateProductRequest()
       );
-      request.product = {};
-      request.product.name = '';
+      request.product ??= {};
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.UpdateProductRequest',
+        ['product', 'name']
+      );
+      request.product.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.updateProduct(request), expectedError);
@@ -1144,26 +1187,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.DeleteProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.DeleteProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
       client.innerApiCalls.deleteProduct = stubSimpleCall(expectedResponse);
       const [response] = await client.deleteProduct(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProduct without error using callback', async () => {
@@ -1175,15 +1218,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.DeleteProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.DeleteProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1206,11 +1246,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProduct with error', async () => {
@@ -1222,26 +1265,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.DeleteProductRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.DeleteProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.deleteProduct = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.deleteProduct(request), expectedError);
-      assert(
-        (client.innerApiCalls.deleteProduct as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteProduct as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteProduct with closed client', async () => {
@@ -1253,7 +1296,11 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.DeleteProductRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.DeleteProductRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.deleteProduct(request), expectedError);
@@ -1270,15 +1317,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.CreateReferenceImageRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.CreateReferenceImageRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ReferenceImage()
       );
@@ -1286,11 +1330,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.createReferenceImage(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createReferenceImage without error using callback', async () => {
@@ -1302,15 +1349,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.CreateReferenceImageRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.CreateReferenceImageRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ReferenceImage()
       );
@@ -1333,11 +1377,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.createReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createReferenceImage with error', async () => {
@@ -1349,26 +1396,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.CreateReferenceImageRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.CreateReferenceImageRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.createReferenceImage = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.createReferenceImage(request), expectedError);
-      assert(
-        (client.innerApiCalls.createReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.createReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes createReferenceImage with closed client', async () => {
@@ -1380,7 +1427,11 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.CreateReferenceImageRequest()
       );
-      request.parent = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.CreateReferenceImageRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.createReferenceImage(request), expectedError);
@@ -1397,15 +1448,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.DeleteReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.DeleteReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1413,11 +1461,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.deleteReferenceImage(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteReferenceImage without error using callback', async () => {
@@ -1429,15 +1480,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.DeleteReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.DeleteReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1460,11 +1508,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.deleteReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteReferenceImage with error', async () => {
@@ -1476,26 +1527,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.DeleteReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.DeleteReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.deleteReferenceImage = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.deleteReferenceImage(request), expectedError);
-      assert(
-        (client.innerApiCalls.deleteReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.deleteReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes deleteReferenceImage with closed client', async () => {
@@ -1507,7 +1558,11 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.DeleteReferenceImageRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.DeleteReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.deleteReferenceImage(request), expectedError);
@@ -1524,26 +1579,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.GetReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.GetReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ReferenceImage()
       );
       client.innerApiCalls.getReferenceImage = stubSimpleCall(expectedResponse);
       const [response] = await client.getReferenceImage(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getReferenceImage without error using callback', async () => {
@@ -1555,15 +1610,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.GetReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.GetReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ReferenceImage()
       );
@@ -1586,11 +1638,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.getReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getReferenceImage with error', async () => {
@@ -1602,26 +1657,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.GetReferenceImageRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.GetReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.getReferenceImage = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.getReferenceImage(request), expectedError);
-      assert(
-        (client.innerApiCalls.getReferenceImage as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.getReferenceImage as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes getReferenceImage with closed client', async () => {
@@ -1633,7 +1688,11 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.GetReferenceImageRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.GetReferenceImageRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(client.getReferenceImage(request), expectedError);
@@ -1650,15 +1709,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.AddProductToProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.AddProductToProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1666,11 +1722,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.addProductToProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.addProductToProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes addProductToProductSet without error using callback', async () => {
@@ -1682,15 +1741,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.AddProductToProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.AddProductToProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1713,11 +1769,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.addProductToProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes addProductToProductSet with error', async () => {
@@ -1729,15 +1788,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.AddProductToProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.AddProductToProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.addProductToProductSet = stubSimpleCall(
         undefined,
@@ -1747,11 +1803,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
         client.addProductToProductSet(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.addProductToProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.addProductToProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes addProductToProductSet with closed client', async () => {
@@ -1763,7 +1822,11 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.AddProductToProductSetRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.AddProductToProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(
@@ -1783,15 +1846,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.RemoveProductFromProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.RemoveProductFromProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1799,11 +1859,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.removeProductFromProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.removeProductFromProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes removeProductFromProductSet without error using callback', async () => {
@@ -1815,15 +1878,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.RemoveProductFromProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.RemoveProductFromProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.protobuf.Empty()
       );
@@ -1846,11 +1906,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.removeProductFromProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes removeProductFromProductSet with error', async () => {
@@ -1862,15 +1925,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.RemoveProductFromProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.RemoveProductFromProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.removeProductFromProductSet = stubSimpleCall(
         undefined,
@@ -1880,11 +1940,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
         client.removeProductFromProductSet(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.removeProductFromProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.removeProductFromProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes removeProductFromProductSet with closed client', async () => {
@@ -1896,7 +1959,11 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.RemoveProductFromProductSetRequest()
       );
-      request.name = '';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.RemoveProductFromProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
       const expectedError = new Error('The client has already been closed.');
       client.close();
       await assert.rejects(
@@ -1916,15 +1983,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ImportProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ImportProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -1933,11 +1997,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const [operation] = await client.importProductSets(request);
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.importProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes importProductSets without error using callback', async () => {
@@ -1949,15 +2016,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ImportProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ImportProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -1987,11 +2051,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       >;
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.importProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes importProductSets with call error', async () => {
@@ -2003,26 +2070,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ImportProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ImportProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.importProductSets = stubLongRunningCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.importProductSets(request), expectedError);
-      assert(
-        (client.innerApiCalls.importProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes importProductSets with LRO error', async () => {
@@ -2034,15 +2101,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ImportProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ImportProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.importProductSets = stubLongRunningCall(
         undefined,
@@ -2051,11 +2115,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       );
       const [operation] = await client.importProductSets(request);
       await assert.rejects(operation.promise(), expectedError);
-      assert(
-        (client.innerApiCalls.importProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.importProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes checkImportProductSetsProgress without error', async () => {
@@ -2110,15 +2177,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.PurgeProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.PurgeProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -2127,11 +2191,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const [operation] = await client.purgeProducts(request);
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.purgeProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes purgeProducts without error using callback', async () => {
@@ -2143,15 +2210,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.PurgeProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.PurgeProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = generateSampleMessage(
         new protos.google.longrunning.Operation()
       );
@@ -2181,11 +2245,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       >;
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.purgeProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes purgeProducts with call error', async () => {
@@ -2197,26 +2264,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.PurgeProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.PurgeProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.purgeProducts = stubLongRunningCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.purgeProducts(request), expectedError);
-      assert(
-        (client.innerApiCalls.purgeProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes purgeProducts with LRO error', async () => {
@@ -2228,15 +2295,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.PurgeProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.PurgeProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.purgeProducts = stubLongRunningCall(
         undefined,
@@ -2245,11 +2309,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       );
       const [operation] = await client.purgeProducts(request);
       await assert.rejects(operation.promise(), expectedError);
-      assert(
-        (client.innerApiCalls.purgeProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.purgeProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes checkPurgeProductsProgress without error', async () => {
@@ -2304,15 +2371,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.ProductSet()
@@ -2327,11 +2391,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       client.innerApiCalls.listProductSets = stubSimpleCall(expectedResponse);
       const [response] = await client.listProductSets(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductSets without error using callback', async () => {
@@ -2343,15 +2410,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.ProductSet()
@@ -2382,11 +2446,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductSets with error', async () => {
@@ -2398,26 +2465,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.listProductSets = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.listProductSets(request), expectedError);
-      assert(
-        (client.innerApiCalls.listProductSets as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductSets as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductSetsStream without error', async () => {
@@ -2429,8 +2496,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.ProductSet()
@@ -2467,11 +2538,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProductSets, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProductSets.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProductSets.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2484,8 +2556,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProductSets.createStream =
         stubPageStreamingCall(undefined, expectedError);
@@ -2511,11 +2587,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProductSets, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProductSets.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProductSets.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2528,8 +2605,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.ProductSet()
@@ -2555,11 +2636,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProductSets.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProductSets.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2572,8 +2654,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductSetsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductSetsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProductSets.asyncIterate =
         stubAsyncIterationCall(undefined, expectedError);
@@ -2591,11 +2677,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProductSets.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProductSets.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
   });
@@ -2610,15 +2697,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.Product()
@@ -2633,11 +2717,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       client.innerApiCalls.listProducts = stubSimpleCall(expectedResponse);
       const [response] = await client.listProducts(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProducts without error using callback', async () => {
@@ -2649,15 +2736,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.Product()
@@ -2688,11 +2772,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProducts with error', async () => {
@@ -2704,26 +2791,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.listProducts = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.listProducts(request), expectedError);
-      assert(
-        (client.innerApiCalls.listProducts as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProducts as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductsStream without error', async () => {
@@ -2735,8 +2822,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.Product()
@@ -2773,11 +2864,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProducts, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProducts.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProducts.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2790,8 +2882,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProducts.createStream = stubPageStreamingCall(
         undefined,
@@ -2819,11 +2915,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProducts, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProducts.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProducts.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2836,8 +2933,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.Product()
@@ -2863,11 +2964,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProducts.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProducts.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -2880,8 +2982,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductsRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductsRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProducts.asyncIterate =
         stubAsyncIterationCall(undefined, expectedError);
@@ -2898,11 +3004,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listProducts.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listProducts.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
   });
@@ -2917,15 +3024,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.ReferenceImage()
@@ -2941,11 +3045,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.listReferenceImages(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listReferenceImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listReferenceImages without error using callback', async () => {
@@ -2957,15 +3064,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.ReferenceImage()
@@ -2998,11 +3102,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listReferenceImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listReferenceImages with error', async () => {
@@ -3014,26 +3121,26 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.listReferenceImages = stubSimpleCall(
         undefined,
         expectedError
       );
       await assert.rejects(client.listReferenceImages(request), expectedError);
-      assert(
-        (client.innerApiCalls.listReferenceImages as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listReferenceImages as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listReferenceImagesStream without error', async () => {
@@ -3045,8 +3152,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.ReferenceImage()
@@ -3084,11 +3195,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listReferenceImages, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listReferenceImages.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listReferenceImages.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3101,8 +3213,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listReferenceImages.createStream =
         stubPageStreamingCall(undefined, expectedError);
@@ -3129,11 +3245,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listReferenceImages, request)
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listReferenceImages.createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listReferenceImages.createStream as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3146,8 +3263,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.ReferenceImage()
@@ -3174,11 +3295,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listReferenceImages.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listReferenceImages.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3191,8 +3313,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListReferenceImagesRequest()
       );
-      request.parent = '';
-      const expectedHeaderRequestParams = 'parent=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListReferenceImagesRequest',
+        ['parent']
+      );
+      request.parent = defaultValue1;
+      const expectedHeaderRequestParams = `parent=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listReferenceImages.asyncIterate =
         stubAsyncIterationCall(undefined, expectedError);
@@ -3210,11 +3336,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
-        (
-          client.descriptors.page.listReferenceImages.asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+      assert(
+        (client.descriptors.page.listReferenceImages.asyncIterate as SinonStub)
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
   });
@@ -3229,15 +3356,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.Product()
@@ -3253,11 +3377,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
         stubSimpleCall(expectedResponse);
       const [response] = await client.listProductsInProductSet(request);
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProductsInProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductsInProductSet without error using callback', async () => {
@@ -3269,15 +3396,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.Product()
@@ -3308,11 +3432,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
-      assert(
-        (client.innerApiCalls.listProductsInProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions /*, callback defined above */)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductsInProductSet with error', async () => {
@@ -3324,15 +3451,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
-      const expectedOptions = {
-        otherArgs: {
-          headers: {
-            'x-goog-request-params': expectedHeaderRequestParams,
-          },
-        },
-      };
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.innerApiCalls.listProductsInProductSet = stubSimpleCall(
         undefined,
@@ -3342,11 +3466,14 @@ describe('v1p4beta1.ProductSearchClient', () => {
         client.listProductsInProductSet(request),
         expectedError
       );
-      assert(
-        (client.innerApiCalls.listProductsInProductSet as SinonStub)
-          .getCall(0)
-          .calledWith(request, expectedOptions, undefined)
-      );
+      const actualRequest = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[0];
+      assert.deepStrictEqual(actualRequest, request);
+      const actualHeaderRequestParams = (
+        client.innerApiCalls.listProductsInProductSet as SinonStub
+      ).getCall(0).args[1].otherArgs.headers['x-goog-request-params'];
+      assert(actualHeaderRequestParams.includes(expectedHeaderRequestParams));
     });
 
     it('invokes listProductsInProductSetStream without error', async () => {
@@ -3358,8 +3485,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.Product()
@@ -3399,12 +3530,15 @@ describe('v1p4beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProductsInProductSet, request)
       );
-      assert.strictEqual(
+      assert(
         (
           client.descriptors.page.listProductsInProductSet
             .createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+        )
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3417,8 +3551,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProductsInProductSet.createStream =
         stubPageStreamingCall(undefined, expectedError);
@@ -3447,12 +3585,15 @@ describe('v1p4beta1.ProductSearchClient', () => {
           .getCall(0)
           .calledWith(client.innerApiCalls.listProductsInProductSet, request)
       );
-      assert.strictEqual(
+      assert(
         (
           client.descriptors.page.listProductsInProductSet
             .createStream as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+        )
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3465,8 +3606,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedResponse = [
         generateSampleMessage(
           new protos.google.cloud.vision.v1p4beta1.Product()
@@ -3493,12 +3638,15 @@ describe('v1p4beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
+      assert(
         (
           client.descriptors.page.listProductsInProductSet
             .asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+        )
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
 
@@ -3511,8 +3659,12 @@ describe('v1p4beta1.ProductSearchClient', () => {
       const request = generateSampleMessage(
         new protos.google.cloud.vision.v1p4beta1.ListProductsInProductSetRequest()
       );
-      request.name = '';
-      const expectedHeaderRequestParams = 'name=';
+      const defaultValue1 = getTypeDefaultValue(
+        '.google.cloud.vision.v1p4beta1.ListProductsInProductSetRequest',
+        ['name']
+      );
+      request.name = defaultValue1;
+      const expectedHeaderRequestParams = `name=${defaultValue1}`;
       const expectedError = new Error('expected');
       client.descriptors.page.listProductsInProductSet.asyncIterate =
         stubAsyncIterationCall(undefined, expectedError);
@@ -3530,12 +3682,15 @@ describe('v1p4beta1.ProductSearchClient', () => {
         ).getCall(0).args[1],
         request
       );
-      assert.strictEqual(
+      assert(
         (
           client.descriptors.page.listProductsInProductSet
             .asyncIterate as SinonStub
-        ).getCall(0).args[2].otherArgs.headers['x-goog-request-params'],
-        expectedHeaderRequestParams
+        )
+          .getCall(0)
+          .args[2].otherArgs.headers['x-goog-request-params'].includes(
+            expectedHeaderRequestParams
+          )
       );
     });
   });