Add test suite; update public API

Author: MaggieKimani1

test/Microsoft.OpenApi.Tests/Models/OpenApiDocumentTests.cs

@@ -12,6 +12,7 @@
 using Microsoft.OpenApi.Interfaces;
 using Microsoft.OpenApi.Models;
 using Microsoft.OpenApi.Readers;
+using Microsoft.OpenApi.Services;
 using Microsoft.OpenApi.Writers;
 using VerifyXunit;
 using Xunit;
@@ -1344,9 +1345,10 @@ public void CopyConstructorForAdvancedDocumentWorks()
             // Arrange & Act
             var doc = new OpenApiDocument(AdvancedDocument);
 
-            // Change value of operation id for a given url
             var docOpId = doc.Paths["/pets"].Operations[OperationType.Get].OperationId = "findAllMyPets";
             var advancedDocOpId = AdvancedDocument.Paths["/pets"].Operations[OperationType.Get].OperationId;
+            var docResponse = doc.Paths["/pets"].Operations[OperationType.Get].Responses["200"].Description = "MyPet";
+            var advancedDocResponse = AdvancedDocument.Paths["/pets"].Operations[OperationType.Get].Responses["200"].Description;
 
             // Assert
             Assert.NotNull(doc.Info);
@@ -1355,6 +1357,7 @@ public void CopyConstructorForAdvancedDocumentWorks()
             Assert.Equal(2, doc.Paths.Count);
             Assert.NotNull(doc.Components);
             Assert.NotEqual(docOpId, advancedDocOpId);
+            Assert.NotEqual(docResponse, advancedDocResponse);
         }
 
         [Fact]

test/Microsoft.OpenApi.Tests/PublicApi/PublicApi.approved.txt

@@ -292,6 +292,14 @@ namespace Microsoft.OpenApi.Extensions
         public static T GetEnumFromDisplayName<T>(this string displayName) { }
     }
 }
+namespace Microsoft.OpenApi.Helpers
+{
+    public class DictionaryCloneHelper
+    {
+        public DictionaryCloneHelper() { }
+        public static System.Collections.Generic.Dictionary<T, U> Clone<T, U>(System.Collections.Generic.IDictionary<T, U> dictionary) { }
+    }
+}
 namespace Microsoft.OpenApi.Interfaces
 {
     public interface IEffective<T>
@@ -587,6 +595,7 @@ namespace Microsoft.OpenApi.Models
     {
         protected OpenApiExtensibleDictionary() { }
         protected OpenApiExtensibleDictionary(System.Collections.Generic.Dictionary<string, T> dictionary = null, System.Collections.Generic.IDictionary<string, Microsoft.OpenApi.Interfaces.IOpenApiExtension> extensions = null) { }
+        public System.Collections.Generic.IDictionary<string, T> Dictionary { get; set; }
         public System.Collections.Generic.IDictionary<string, Microsoft.OpenApi.Interfaces.IOpenApiExtension> Extensions { get; set; }
         public void SerializeAsV2(Microsoft.OpenApi.Writers.IOpenApiWriter writer) { }
         public void SerializeAsV3(Microsoft.OpenApi.Writers.IOpenApiWriter writer) { }