Avoid using virtual calls in constructor

Author: MaggieKimani1

src/Microsoft.OpenApi/Models/OpenApiHeader.cs

@@ -109,7 +109,7 @@ public OpenApiHeader(OpenApiHeader header)
             Style = header?.Style ?? Style;
             Explode = header?.Explode ?? Explode;
             AllowReserved = header?.AllowReserved ?? AllowReserved;
-            Schema = JsonNodeCloneHelper.CloneJsonSchema(Schema);
+            Schema = InitializeSchema();
             Example = JsonNodeCloneHelper.Clone(header?.Example);
             Examples = header?.Examples != null ? new Dictionary<string, OpenApiExample>(header.Examples) : null;
             Content = header?.Content != null ? new Dictionary<string, OpenApiMediaType>(header.Content) : null;
@@ -299,5 +299,14 @@ public void SerializeAsV2WithoutReference(IOpenApiWriter writer)
 
             writer.WriteEndObject();
         }
+
+        /// <summary>
+        /// Clone a JSON schema instance
+        /// </summary>
+        /// <returns></returns>
+        protected JsonSchema InitializeSchema()
+        {
+            return JsonNodeCloneHelper.CloneJsonSchema(Schema);
+        }
     }
 }

src/Microsoft.OpenApi/Models/OpenApiMediaType.cs

@@ -57,7 +57,7 @@ public OpenApiMediaType() { }
         /// </summary>
         public OpenApiMediaType(OpenApiMediaType mediaType)
         {
-            Schema = JsonNodeCloneHelper.CloneJsonSchema(Schema);
+            Schema = InitializeSchema();
             Example = JsonNodeCloneHelper.Clone(mediaType?.Example);
             Examples = mediaType?.Examples != null ? new Dictionary<string, OpenApiExample>(mediaType.Examples) : null;
             Encoding = mediaType?.Encoding != null ? new Dictionary<string, OpenApiEncoding>(mediaType.Encoding) : null;
@@ -115,5 +115,14 @@ public void SerializeAsV2(IOpenApiWriter writer)
         {
             // Media type does not exist in V2.
         }
+
+        /// <summary>
+        /// Clones a JSON schema instance
+        /// </summary>
+        /// <returns></returns>
+        protected JsonSchema InitializeSchema()
+        {
+            return JsonNodeCloneHelper.CloneJsonSchema(Schema);
+        }
     }
 }

src/Microsoft.OpenApi/Models/OpenApiParameter.cs

@@ -163,7 +163,7 @@ public OpenApiParameter(OpenApiParameter parameter)
             Style = parameter?.Style ?? Style;
             Explode = parameter?.Explode ?? Explode;
             AllowReserved = parameter?.AllowReserved ?? AllowReserved;
-            Schema = JsonNodeCloneHelper.CloneJsonSchema(Schema);
+            Schema = InitializeSchema();
             Examples = parameter?.Examples != null ? new Dictionary<string, OpenApiExample>(parameter.Examples) : null;
             Example = JsonNodeCloneHelper.Clone(parameter?.Example);
             Content = parameter?.Content != null ? new Dictionary<string, OpenApiMediaType>(parameter.Content) : null;
@@ -447,6 +447,15 @@ public void SerializeAsV2WithoutReference(IOpenApiWriter writer)
 
             return Style;
         }
+
+        /// <summary>
+        /// Clones an instance of a JSON schema
+        /// </summary>
+        /// <returns></returns>
+        protected JsonSchema InitializeSchema()
+        {
+            return JsonNodeCloneHelper.CloneJsonSchema(Schema);
+        }
     }
 
     /// <summary>