♻️ Model#global_id_method instead of Model#global_id_column

`Model.primary_key` is actually irrelevant to this feature, the only
thing that matters is the model method.

For composite keys, or primary keys not named "id", we still get the
important value from `Model#id`, the only time we don't is when we need
to use a non-PK column.

lib/global_id/identification.rb

@@ -36,8 +36,8 @@ def global_id_column(column_name = nil)
       end
     end
 
-    def global_id_column
-      self.class.global_id_column || self.class.try(:primary_key) || :id
+    def global_id_method
+      self.class.global_id_column || :id
     end
 
     # Returns the Global ID of the model.

lib/global_id/uri/gid.rb

@@ -70,9 +70,7 @@ def parse(uri)
       #
       #   URI::GID.create('bcx', Person.find(5), database: 'superhumans')
       def create(app, model, params = nil)
-        model_id_method = model.id.is_a?(Array) ? :id : model.global_id_column
-
-        build app: app, model_name: model.class.name, model_id: model.send(model_id_method), params: params
+        build app: app, model_name: model.class.name, model_id: model.send(model.global_id_method), params: params
       end
 
       # Create a new URI::GID from components with argument check.

test/models/person.rb

@@ -41,10 +41,6 @@ class PersonUuid < Person
   def self.primary_key
     :uuid
   end
-
-  def uuid
-    id
-  end
 end
 
 class Person::Scoped < Person