diff --git a/src/Iceberg-Git-CLI/UnifiedDiff.class.st b/src/Iceberg-Git-CLI/UnifiedDiff.class.st
index fde7b89..37e322f 100644
--- a/src/Iceberg-Git-CLI/UnifiedDiff.class.st
+++ b/src/Iceberg-Git-CLI/UnifiedDiff.class.st
@@ -16,6 +16,26 @@ Class {
 	#category : #'Iceberg-Git-CLI-Pure'
 }
 
+{ #category : #operations }
+UnifiedDiff >> applyTo: input [
+	| lines lineNumber|
+	lines := input lines.
+	lineNumber := 1.
+	^ String streamContents: [ :out |
+		self changeChunks do: [ :changeChunk | 
+			[ lineNumber < changeChunk oldStart ]
+				whileTrue: [
+					out nextPutAll: (lines at: lineNumber); cr.
+					lineNumber := lineNumber + 1 ].
+			changeChunk newContentsLines do: [ :line |
+				out next: line size - 1 putAll: line startingAt: 2; cr ].
+			lineNumber := lineNumber + changeChunk oldCount ].
+		[ lineNumber <= lines size ]
+			whileTrue: [
+				out nextPutAll: (lines at: lineNumber); cr.
+				lineNumber := lineNumber + 1 ] ]
+]
+
 { #category : #accessing }
 UnifiedDiff >> changeChunks [
 	^ changeChunks
diff --git a/src/Iceberg-Git-CLI/UnifiedDiffExamples.class.st b/src/Iceberg-Git-CLI/UnifiedDiffExamples.class.st
index 1d48d12..ead6f67 100644
--- a/src/Iceberg-Git-CLI/UnifiedDiffExamples.class.st
+++ b/src/Iceberg-Git-CLI/UnifiedDiffExamples.class.st
@@ -235,6 +235,65 @@ to this document.
 '
 ]
 
+{ #category : #accessing }
+UnifiedDiffExamples >> exampleOneContents [
+	<gtExample>
+	^ ($A to: $Z) flatCollect: [ :each | String with: each with: Character cr ] as: String
+]
+
+{ #category : #accessing }
+UnifiedDiffExamples >> exampleOneTwoGitUnifiedDiff [
+	<gtExample>
+	
+	| unifiedDiff output |
+	unifiedDiff := UnifiedDiff new
+		readFromLines: self exampleOneTwoGitUnifiedDiffOutput lines readStream.
+
+	output := unifiedDiff applyTo: self exampleOneContents.
+
+	self assert: output equals: self exampleTwoContents.
+
+	^ unifiedDiff
+]
+
+{ #category : #accessing }
+UnifiedDiffExamples >> exampleOneTwoGitUnifiedDiffOutput [
+	<gtExample>
+
+	"git diff foo.txt bar.txt"
+
+	^ 'diff --git a/foo.txt b/bar.txt
+index a6f1d23..c5f54f4 100644
+--- a/foo.txt
++++ b/bar.txt
+@@ -2,7 +2,7 @@ A
+ B
+ C
+ D
+-E
++e
+ F
+ G
+ H
+@@ -10,6 +10,7 @@ I
+ J
+ K
+ L
++x
+ M
+ N
+ O
+@@ -18,7 +19,6 @@ Q
+ R
+ S
+ T
+-U
+ V
+ W
+ X
+'
+]
+
 { #category : #accessing }
 UnifiedDiffExamples >> exampleOriginalContents [
 	<gtExample>
@@ -312,3 +371,17 @@ UnifiedDiffExamples >> exampleStandardUnifiedDiffOutput [
 +to this document.
 '
 ]
+
+{ #category : #accessing }
+UnifiedDiffExamples >> exampleTwoContents [
+	<gtExample>
+	| alphabet |
+	alphabet := ($A to: $Z) asOrderedCollection.
+	"modify: $E -> $e"
+	alphabet at: 5 put: $e.
+	"delete: $U"
+	alphabet removeAt: 21.
+	"add: $x after $L"
+	alphabet add: $x afterIndex: 12.
+	^ alphabet flatCollect: [ :each | String with: each with: Character cr ] as: String
+]