diff --git a/src/Microsoft.OpenApi.Readers/YamlReaders/MapNode.cs b/src/Microsoft.OpenApi.Readers/YamlReaders/MapNode.cs
index 4b3d531f4..88737a140 100644
--- a/src/Microsoft.OpenApi.Readers/YamlReaders/MapNode.cs
+++ b/src/Microsoft.OpenApi.Readers/YamlReaders/MapNode.cs
@@ -70,11 +70,11 @@ public string GetScalarValue(ValueNode key)
             return scalarNode.Value;
         }
 
-        public T GetReferencedObject<T>(string refPointer) where T : IReference
+        public T GetReferencedObject<T>(string refPointer) where T : IOpenApiReference
         {
             return (T)this.Context.GetReferencedObject(refPointer); 
         }
-        public T CreateOrReferenceDomainObject<T>(Func<T> factory) where T: IReference
+        public T CreateOrReferenceDomainObject<T>(Func<T> factory) where T: IOpenApiReference
         {
             T domainObject;
             var refPointer = GetReferencePointer(); // What should the DOM of a reference look like?
diff --git a/src/Microsoft.OpenApi.Readers/YamlReaders/OpenApiV2Builder.cs b/src/Microsoft.OpenApi.Readers/YamlReaders/OpenApiV2Builder.cs
index 0e87d2c5e..789b47bf5 100644
--- a/src/Microsoft.OpenApi.Readers/YamlReaders/OpenApiV2Builder.cs
+++ b/src/Microsoft.OpenApi.Readers/YamlReaders/OpenApiV2Builder.cs
@@ -27,7 +27,7 @@ internal static class OpenApiV2Builder
 
 
 
-        private static void MakeServers(List<OpenApiServer> servers, ParsingContext context)
+        private static void MakeServers(IList<OpenApiServer> servers, ParsingContext context)
         {
             string host = context.GetTempStorage<string>("host");
             string basePath = context.GetTempStorage<string>("basePath");
@@ -47,7 +47,7 @@ private static void MakeServers(List<OpenApiServer> servers, ParsingContext cont
         public static PatternFieldMap<OpenApiDocument> OpenApiPatternFields = new PatternFieldMap<OpenApiDocument>
         {
             // We have no semantics to verify X- nodes, therefore treat them as just values.
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiDocument LoadOpenApi(RootNode rootNode)
@@ -84,7 +84,7 @@ public static OpenApiDocument LoadOpenApi(RootNode rootNode)
 
         public static PatternFieldMap<OpenApiInfo> InfoPatternFields = new PatternFieldMap<OpenApiInfo>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k,  new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k,  new OpenApiString(n.GetScalarValue())) }
         };
 
 
@@ -115,7 +115,7 @@ public static OpenApiInfo LoadInfo(ParseNode node)
 
         public static PatternFieldMap<OpenApiContact> ContactPatternFields = new PatternFieldMap<OpenApiContact>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k,  new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k,  new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiContact LoadContact(ParseNode node)
@@ -139,7 +139,7 @@ public static OpenApiContact LoadContact(ParseNode node)
 
         public static PatternFieldMap<OpenApiLicense> LicensePatternFields = new PatternFieldMap<OpenApiLicense>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k,  new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k,  new OpenApiString(n.GetScalarValue())) }
         };
 
         internal static OpenApiLicense LoadLicense(ParseNode node)
@@ -164,7 +164,7 @@ internal static OpenApiLicense LoadLicense(ParseNode node)
         public static PatternFieldMap<OpenApiPaths> PathsPatternFields = new PatternFieldMap<OpenApiPaths>
         {
             { (s)=> s.StartsWith("/"), (o,k,n)=> o.Add(k, OpenApiV2Builder.LoadPathItem(n)    ) },
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiPaths LoadPaths(ParseNode node)
@@ -190,7 +190,7 @@ public static OpenApiPaths LoadPaths(ParseNode node)
 
         private static PatternFieldMap<OpenApiPathItem> PathItemPatternFields = new PatternFieldMap<OpenApiPathItem>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k,  new GenericOpenApiExtension(n.GetScalarValue())) },
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k,  new OpenApiString(n.GetScalarValue())) },
             { (s)=> "get,put,post,delete,patch,options,head,patch".Contains(s),
                 (o,k,n)=> o.AddOperation(OperationTypeExtensions.ParseOperationType(k), OpenApiV2Builder.LoadOperation(n)    ) }
         };
@@ -228,7 +228,7 @@ public static OpenApiPathItem LoadPathItem(ParseNode node)
 
         private static PatternFieldMap<OpenApiOperation> OperationPatternFields = new PatternFieldMap<OpenApiOperation>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) },
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) },
         };
 
         internal static OpenApiOperation LoadOperation(ParseNode node)
@@ -418,7 +418,7 @@ private static void ProcessIn(OpenApiParameter o, ParseNode n)
 
         private static PatternFieldMap<OpenApiParameter> ParameterPatternFields = new PatternFieldMap<OpenApiParameter>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) },
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) },
         };
 
 
@@ -465,7 +465,7 @@ public static OpenApiParameter LoadParameter(ParseNode node)
 
         private static PatternFieldMap<OpenApiResponse> ResponsePatternFields = new PatternFieldMap<OpenApiResponse>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k,  new GenericOpenApiExtension(n.GetScalarValue())) },
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k,  new OpenApiString(n.GetScalarValue())) },
         };
 
         public static OpenApiResponse LoadResponse(ParseNode node)
@@ -523,7 +523,7 @@ private static void ProcessProduces(OpenApiResponse response, ParsingContext con
 
         private static PatternFieldMap<OpenApiHeader> HeaderPatternFields = new PatternFieldMap<OpenApiHeader>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k,  new GenericOpenApiExtension(n.GetScalarValue())) },
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k,  new OpenApiString(n.GetScalarValue())) },
         };
 
 
@@ -555,7 +555,7 @@ public static OpenApiHeader LoadHeader(ParseNode node)
 
         private static PatternFieldMap<OpenApiExample> ExamplePatternFields = new PatternFieldMap<OpenApiExample>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k,  new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k,  new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiExample LoadExample(ParseNode node)
@@ -643,7 +643,7 @@ internal static OpenApiTag LoadTag(ParseNode n)
 
         private static PatternFieldMap<OpenApiSchema> SchemaPatternFields = new PatternFieldMap<OpenApiSchema>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
 
@@ -689,7 +689,7 @@ public static OpenApiSchema LoadSchema(ParseNode node)
 
         private static PatternFieldMap<OpenApiSecurityScheme> SecuritySchemePatternFields = new PatternFieldMap<OpenApiSecurityScheme>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiSecurityScheme LoadSecurityScheme(ParseNode node)
@@ -790,9 +790,9 @@ private static string GetReferenceTypeName(ReferenceType referenceType)
         }
 
 
-        public static IReference LoadReference(OpenApiReference reference, object rootNode)
+        public static IOpenApiReference LoadReference(OpenApiReference reference, object rootNode)
         {
-            IReference referencedObject = null;
+            IOpenApiReference referencedObject = null;
             ParseNode node = ((RootNode)rootNode).Find(GetPointer(reference));
 
             if (node == null &&  reference.ReferenceType != ReferenceType.Tags ) return null;
diff --git a/src/Microsoft.OpenApi.Readers/YamlReaders/OpenApiV3Builder.cs b/src/Microsoft.OpenApi.Readers/YamlReaders/OpenApiV3Builder.cs
index 6653688ea..b921ceb86 100644
--- a/src/Microsoft.OpenApi.Readers/YamlReaders/OpenApiV3Builder.cs
+++ b/src/Microsoft.OpenApi.Readers/YamlReaders/OpenApiV3Builder.cs
@@ -22,7 +22,7 @@ internal static class OpenApiV3Builder
         public static PatternFieldMap<OpenApiDocument> OpenApiPatternFields = new PatternFieldMap<OpenApiDocument>
         {
             // We have no semantics to verify X- nodes, therefore treat them as just values.
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiDocument LoadOpenApi(RootNode rootNode)
@@ -56,10 +56,9 @@ public static OpenApiDocument LoadOpenApi(RootNode rootNode)
 
         public static PatternFieldMap<OpenApiInfo> InfoPatternFields = new PatternFieldMap<OpenApiInfo>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
-
         public static OpenApiInfo LoadInfo(ParseNode node)
         {
             var mapNode = node.CheckMapNode("Info");
@@ -85,7 +84,7 @@ public static OpenApiInfo LoadInfo(ParseNode node)
 
         public static PatternFieldMap<OpenApiContact> ContactPatternFields = new PatternFieldMap<OpenApiContact>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiContact LoadContact(ParseNode node)
@@ -109,7 +108,7 @@ public static OpenApiContact LoadContact(ParseNode node)
 
         public static PatternFieldMap<OpenApiLicense> LicensePatternFields = new PatternFieldMap<OpenApiLicense>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
         internal static OpenApiLicense LoadLicense(ParseNode node)
@@ -136,7 +135,7 @@ internal static OpenApiLicense LoadLicense(ParseNode node)
 
         private static PatternFieldMap<OpenApiServer> ServerPatternFields = new PatternFieldMap<OpenApiServer>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, n.GetScalarValue()) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiServer LoadServer(ParseNode node)
@@ -163,7 +162,7 @@ public static OpenApiServer LoadServer(ParseNode node)
 
         private static PatternFieldMap<OpenApiServerVariable> ServerVariablePatternFields = new PatternFieldMap<OpenApiServerVariable>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, n.GetScalarValue()) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiServerVariable LoadServerVariable(ParseNode node)
@@ -195,7 +194,7 @@ public static OpenApiServerVariable LoadServerVariable(ParseNode node)
 
         public static PatternFieldMap<OpenApiComponents> ComponentsPatternFields = new PatternFieldMap<OpenApiComponents>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiComponents LoadComponents(ParseNode node)
@@ -219,7 +218,7 @@ public static OpenApiComponents LoadComponents(ParseNode node)
         public static PatternFieldMap<OpenApiPaths> PathsPatternFields = new PatternFieldMap<OpenApiPaths>
         {
             { (s)=> s.StartsWith("/"), (o,k,n)=> o.Add(k, LoadPathItem(n)    ) },
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiPaths LoadPaths(ParseNode node)
@@ -248,7 +247,7 @@ public static OpenApiPaths LoadPaths(ParseNode node)
 
         private static PatternFieldMap<OpenApiPathItem> PathItemPatternFields = new PatternFieldMap<OpenApiPathItem>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) },
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) },
             { (s)=> "get,put,post,delete,patch,options,head,patch,trace".Contains(s),
                 (o,k,n)=> o.AddOperation(OperationTypeExtensions.ParseOperationType(k), LoadOperation(n)    ) }
         };
@@ -287,7 +286,7 @@ public static OpenApiPathItem LoadPathItem(ParseNode node)
 
         private static PatternFieldMap<OpenApiOperation> OperationPatternFields = new PatternFieldMap<OpenApiOperation>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) },
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) },
         };
 
         internal static OpenApiOperation LoadOperation(ParseNode node)
@@ -350,7 +349,7 @@ public static OpenApiExternalDocs LoadExternalDocs(ParseNode node)
 
         private static PatternFieldMap<OpenApiParameter> ParameterPatternFields = new PatternFieldMap<OpenApiParameter>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) },
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) },
         };
 
 
@@ -384,7 +383,7 @@ public static OpenApiParameter LoadParameter(ParseNode node)
 
         private static PatternFieldMap<OpenApiRequestBody> RequestBodyPatternFields = new PatternFieldMap<OpenApiRequestBody>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, n.GetScalarValue()) },
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) },
         };
 
         public static OpenApiRequestBody LoadRequestBody(ParseNode node)
@@ -414,7 +413,7 @@ public static OpenApiRequestBody LoadRequestBody(ParseNode node)
 
         private static PatternFieldMap<OpenApiMediaType> MediaTypePatternFields = new PatternFieldMap<OpenApiMediaType>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, n.GetScalarValue()) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiMediaType LoadMediaType(ParseNode node)
@@ -453,7 +452,7 @@ public static OpenApiMediaType LoadMediaType(ParseNode node)
 
         private static PatternFieldMap<OpenApiResponse> ResponsePatternFields = new PatternFieldMap<OpenApiResponse>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) },
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) },
         };
 
         public static OpenApiResponse LoadResponse(ParseNode node)
@@ -512,10 +511,9 @@ public static OpenApiCallback LoadCallback(ParseNode node)
 
         private static PatternFieldMap<OpenApiLink> LinkPatternFields = new PatternFieldMap<OpenApiLink>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, n.GetScalarValue()) },
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) },
         };
 
-
         public static OpenApiLink LoadLink(ParseNode node)
         {
             var mapNode = node.CheckMapNode("link");
@@ -547,7 +545,7 @@ public static OpenApiLink LoadLink(ParseNode node)
 
         private static PatternFieldMap<OpenApiHeader> HeaderPatternFields = new PatternFieldMap<OpenApiHeader>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) },
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) },
         };
 
 
@@ -575,7 +573,7 @@ public static OpenApiHeader LoadHeader(ParseNode node)
 
         private static PatternFieldMap<OpenApiExample> ExamplePatternFields = new PatternFieldMap<OpenApiExample>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiExample LoadExample(ParseNode node)
@@ -676,7 +674,7 @@ internal static OpenApiTag LoadTag(ParseNode n)
 
         private static PatternFieldMap<OpenApiSchema> SchemaPatternFields = new PatternFieldMap<OpenApiSchema>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiSchema LoadSchema(string schema)
@@ -727,7 +725,7 @@ public static OpenApiSchema LoadSchema(ParseNode node)
 
         private static PatternFieldMap<OpenApiSecurityScheme> SecuritySchemePatternFields = new PatternFieldMap<OpenApiSecurityScheme>
         {
-            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new GenericOpenApiExtension(n.GetScalarValue())) }
+            { (s)=> s.StartsWith("x-"), (o,k,n)=> o.Extensions.Add(k, new OpenApiString(n.GetScalarValue())) }
         };
 
         public static OpenApiSecurityScheme LoadSecurityScheme(ParseNode node)
@@ -764,9 +762,9 @@ public static OpenApiSecurityRequirement LoadSecurityRequirement(ParseNode node)
 
         #endregion
 
-        public static IReference LoadReference(OpenApiReference pointer, object rootNode)
+        public static IOpenApiReference LoadReference(OpenApiReference pointer, object rootNode)
         {
-            IReference referencedObject = null;
+            IOpenApiReference referencedObject = null;
 
             var node = ((RootNode)rootNode).Find(pointer.GetLocalPointer());
             if (node == null && pointer.ReferenceType != ReferenceType.Tags) return null;
diff --git a/src/Microsoft.OpenApi.Readers/YamlReaders/ParseNode.cs b/src/Microsoft.OpenApi.Readers/YamlReaders/ParseNode.cs
index 48a112464..843f13acf 100644
--- a/src/Microsoft.OpenApi.Readers/YamlReaders/ParseNode.cs
+++ b/src/Microsoft.OpenApi.Readers/YamlReaders/ParseNode.cs
@@ -49,7 +49,7 @@ public virtual Dictionary<string, T> CreateMap<T>(Func<MapNode, T> map)
         {
             throw new OpenApiException("Cannot create map");
         }
-        public virtual Dictionary<string, T> CreateMapWithReference<T>(string refpointer, Func<MapNode, T> map) where T : class, IReference
+        public virtual Dictionary<string, T> CreateMapWithReference<T>(string refpointer, Func<MapNode, T> map) where T : class, IOpenApiReference
         {
             throw new OpenApiException("Cannot create map from reference");
         }
diff --git a/src/Microsoft.OpenApi.Readers/YamlReaders/ParsingContext.cs b/src/Microsoft.OpenApi.Readers/YamlReaders/ParsingContext.cs
index 760897287..401491162 100644
--- a/src/Microsoft.OpenApi.Readers/YamlReaders/ParsingContext.cs
+++ b/src/Microsoft.OpenApi.Readers/YamlReaders/ParsingContext.cs
@@ -15,9 +15,9 @@ public class ParsingContext : ILog<OpenApiError>
 
         private readonly Stack<string> previousPointers = new Stack<string>();
 
-        private IReferenceService referenceService;
+        private IOpenApiReferenceService referenceService;
 
-        private readonly Dictionary<string, IReference> referenceStore = new Dictionary<string, IReference>();
+        private readonly Dictionary<string, IOpenApiReference> referenceStore = new Dictionary<string, IOpenApiReference>();
 
         private readonly Dictionary<string, object> tempStorage = new Dictionary<string, object>();
 
@@ -37,15 +37,15 @@ public string GetLocation()
             return "#/" + string.Join("/", currentLocation.Reverse().ToArray());
         }
 
-        public IReference GetReferencedObject(string pointer)
+        public IOpenApiReference GetReferencedObject(string pointer)
         {
             var reference = referenceService.ParseReference(pointer);
             return GetReferencedObject(reference);
         }
 
-        public IReference GetReferencedObject(OpenApiReference reference)
+        public IOpenApiReference GetReferencedObject(OpenApiReference reference)
         {
-            IReference returnValue = null;
+            IOpenApiReference returnValue = null;
             referenceStore.TryGetValue(reference.ToString(), out returnValue);
 
             if (returnValue == null)
@@ -83,7 +83,7 @@ public T GetTempStorage<T>(string key) where T : class
             return null;
         }
 
-        public void SetReferenceService(IReferenceService referenceService)
+        public void SetReferenceService(IOpenApiReferenceService referenceService)
         {
             this.referenceService = referenceService;
         }
diff --git a/src/Microsoft.OpenApi.Readers/YamlReaders/ReferenceService.cs b/src/Microsoft.OpenApi.Readers/YamlReaders/ReferenceService.cs
index aeff55918..0bef85fc7 100644
--- a/src/Microsoft.OpenApi.Readers/YamlReaders/ReferenceService.cs
+++ b/src/Microsoft.OpenApi.Readers/YamlReaders/ReferenceService.cs
@@ -3,9 +3,9 @@
 
 namespace Microsoft.OpenApi.Readers.YamlReaders
 {
-    internal class ReferenceService : IReferenceService
+    internal class ReferenceService : IOpenApiReferenceService
     {
-        public Func<OpenApiReference, object, IReference> loadReference { get; set; }
+        public Func<OpenApiReference, object, IOpenApiReference> loadReference { get; set; }
         public Func<string, OpenApiReference> parseReference { get; set; }
 
         private object rootNode;
@@ -14,7 +14,7 @@ public ReferenceService(object rootNode)
         {
             this.rootNode = rootNode;
         }
-        public IReference LoadReference(OpenApiReference reference)
+        public IOpenApiReference LoadReference(OpenApiReference reference)
         {
             var referenceObject = this.loadReference(reference,this.rootNode);
             if (referenceObject == null)
diff --git a/src/Microsoft.OpenApi/IOpenApiExtension.cs b/src/Microsoft.OpenApi/Abstracts/IOpenApiElement.cs
similarity index 65%
rename from src/Microsoft.OpenApi/IOpenApiExtension.cs
rename to src/Microsoft.OpenApi/Abstracts/IOpenApiElement.cs
index 6dbc58070..265bab2e7 100644
--- a/src/Microsoft.OpenApi/IOpenApiExtension.cs
+++ b/src/Microsoft.OpenApi/Abstracts/IOpenApiElement.cs
@@ -1,12 +1,15 @@
 //---------------------------------------------------------------------
-// <copyright file="IOpenApiExtension.cs" company="Microsoft">
+// <copyright file="IOpenApiElement.cs" company="Microsoft">
 //      Copyright (C) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
 // </copyright>
 //---------------------------------------------------------------------
 
 namespace Microsoft.OpenApi
 {
-    public interface IOpenApiExtension
+    /// <summary>
+    /// Represents an Open API element.
+    /// </summary>
+    public interface IOpenApiElement
     {
     }
 }
diff --git a/src/Microsoft.OpenApi/Abstracts/IOpenApiExtension.cs b/src/Microsoft.OpenApi/Abstracts/IOpenApiExtension.cs
new file mode 100644
index 000000000..4b078bee0
--- /dev/null
+++ b/src/Microsoft.OpenApi/Abstracts/IOpenApiExtension.cs
@@ -0,0 +1,21 @@
+//---------------------------------------------------------------------
+// <copyright file="IOpenApiExtension.cs" company="Microsoft">
+//      Copyright (C) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
+// </copyright>
+//---------------------------------------------------------------------
+
+using System.Collections.Generic;
+
+namespace Microsoft.OpenApi
+{
+    /// <summary>
+    /// Represents an Extensible Open API element.
+    /// </summary>
+    public interface IOpenApiExtension : IOpenApiElement
+    {
+        /// <summary>
+        /// Specification extensions.
+        /// </summary>
+        IDictionary<string, IOpenApiAny> Extensions { get; set; }
+    }
+}
diff --git a/src/Microsoft.OpenApi/IReference.cs b/src/Microsoft.OpenApi/Abstracts/IOpenApiReference.cs
similarity index 57%
rename from src/Microsoft.OpenApi/IReference.cs
rename to src/Microsoft.OpenApi/Abstracts/IOpenApiReference.cs
index 11ef32372..48e86fcec 100644
--- a/src/Microsoft.OpenApi/IReference.cs
+++ b/src/Microsoft.OpenApi/Abstracts/IOpenApiReference.cs
@@ -1,13 +1,19 @@
 //---------------------------------------------------------------------
-// <copyright file="IReference.cs" company="Microsoft">
+// <copyright file="IOpenApiReference.cs" company="Microsoft">
 //      Copyright (C) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
 // </copyright>
 //---------------------------------------------------------------------
 
 namespace Microsoft.OpenApi
 {
-    public interface IReference
+    /// <summary>
+    /// Represents an Open API element is referencable.
+    /// </summary>
+    public interface IOpenApiReference : IOpenApiElement
     {
+        /// <summary>
+        /// Reference object.
+        /// </summary>
         OpenApiReference Pointer { get; set; }
     }
 }
diff --git a/src/Microsoft.OpenApi/IReferenceService.cs b/src/Microsoft.OpenApi/Abstracts/IOpenApiReferenceService.cs
similarity index 67%
rename from src/Microsoft.OpenApi/IReferenceService.cs
rename to src/Microsoft.OpenApi/Abstracts/IOpenApiReferenceService.cs
index 0108b3f7c..a0baea3a6 100644
--- a/src/Microsoft.OpenApi/IReferenceService.cs
+++ b/src/Microsoft.OpenApi/Abstracts/IOpenApiReferenceService.cs
@@ -1,14 +1,14 @@
 //---------------------------------------------------------------------
-// <copyright file="IReferenceService.cs" company="Microsoft">
+// <copyright file="IOpenApiReferenceService.cs" company="Microsoft">
 //      Copyright (C) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
 // </copyright>
 //---------------------------------------------------------------------
 
 namespace Microsoft.OpenApi
 {
-    public interface IReferenceService
+    public interface IOpenApiReferenceService
     {
-        IReference LoadReference(OpenApiReference reference);
+        IOpenApiReference LoadReference(OpenApiReference reference);
         OpenApiReference ParseReference(string pointer);
     }
 }
diff --git a/src/Microsoft.OpenApi/GenericOpenApiExtension.cs b/src/Microsoft.OpenApi/GenericOpenApiExtension.cs
deleted file mode 100644
index 05dbc77c0..000000000
--- a/src/Microsoft.OpenApi/GenericOpenApiExtension.cs
+++ /dev/null
@@ -1,17 +0,0 @@
-//---------------------------------------------------------------------
-// <copyright file="GenericOpenApiExtension.cs" company="Microsoft">
-//      Copyright (C) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
-// </copyright>
-//---------------------------------------------------------------------
-
-namespace Microsoft.OpenApi
-{
-    public class GenericOpenApiExtension : IOpenApiExtension
-    {
-        string node;
-        public GenericOpenApiExtension(string n)
-        {
-            this.node = n;
-        }
-    }
-}
diff --git a/src/Microsoft.OpenApi/Models/OpenApiCallback.cs b/src/Microsoft.OpenApi/Models/OpenApiCallback.cs
index 792f10d79..1a837a7cc 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiCallback.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiCallback.cs
@@ -11,12 +11,12 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Callback Object: A map of possible out-of band callbacks related to the parent operation.
     /// </summary>
-    public class OpenApiCallback : IReference
+    public class OpenApiCallback : IOpenApiReference, IOpenApiExtension
     {
         public Dictionary<RuntimeExpression, OpenApiPathItem> PathItems { get; set; } = new Dictionary<RuntimeExpression, OpenApiPathItem>();
 
         public OpenApiReference Pointer { get; set; }
 
-        public Dictionary<string, IOpenApiAny> Extensions { get; set; }
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
     }
 }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiComponents.cs b/src/Microsoft.OpenApi/Models/OpenApiComponents.cs
index 3946ff562..f03a45ac3 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiComponents.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiComponents.cs
@@ -11,18 +11,18 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Components Object.
     /// </summary>
-    public class OpenApiComponents
+    public class OpenApiComponents : IOpenApiExtension
     {
-        public Dictionary<string, OpenApiSchema> Schemas { get; set; } = new Dictionary<string, OpenApiSchema>();
-        public Dictionary<string, OpenApiResponse> Responses { get; set; } = new Dictionary<string, OpenApiResponse>();
-        public Dictionary<string, OpenApiParameter> Parameters { get; set; } = new Dictionary<string, OpenApiParameter>();
-        public Dictionary<string, OpenApiExample> Examples { get; set; } = new Dictionary<string, OpenApiExample>();
-        public Dictionary<string, OpenApiRequestBody> RequestBodies { get; set; } = new Dictionary<string, OpenApiRequestBody>();
-        public Dictionary<string, OpenApiHeader> Headers { get; set; } = new Dictionary<string, OpenApiHeader>();
-        public Dictionary<string, OpenApiSecurityScheme> SecuritySchemes { get; set; } = new Dictionary<string, OpenApiSecurityScheme>();
-        public Dictionary<string, OpenApiLink> Links { get; set; } = new Dictionary<string, OpenApiLink>();
-        public Dictionary<string, OpenApiCallback> Callbacks { get; set; } = new Dictionary<string, OpenApiCallback>();
-        public Dictionary<string, IOpenApiExtension> Extensions { get; set; } = new Dictionary<string, IOpenApiExtension>();
+        public IDictionary<string, OpenApiSchema> Schemas { get; set; } = new Dictionary<string, OpenApiSchema>();
+        public IDictionary<string, OpenApiResponse> Responses { get; set; } = new Dictionary<string, OpenApiResponse>();
+        public IDictionary<string, OpenApiParameter> Parameters { get; set; } = new Dictionary<string, OpenApiParameter>();
+        public IDictionary<string, OpenApiExample> Examples { get; set; } = new Dictionary<string, OpenApiExample>();
+        public IDictionary<string, OpenApiRequestBody> RequestBodies { get; set; } = new Dictionary<string, OpenApiRequestBody>();
+        public IDictionary<string, OpenApiHeader> Headers { get; set; } = new Dictionary<string, OpenApiHeader>();
+        public IDictionary<string, OpenApiSecurityScheme> SecuritySchemes { get; set; } = new Dictionary<string, OpenApiSecurityScheme>();
+        public IDictionary<string, OpenApiLink> Links { get; set; } = new Dictionary<string, OpenApiLink>();
+        public IDictionary<string, OpenApiCallback> Callbacks { get; set; } = new Dictionary<string, OpenApiCallback>();
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
 
         public bool IsEmpty()
         {
@@ -34,9 +34,7 @@ public bool IsEmpty()
                 || this.Headers.Count > 0 
                 || this.SecuritySchemes.Count > 0
                 || this.Links.Count > 0
-                || this.Callbacks.Count > 0 
-                || this.Extensions.Count > 0);
-
+                || this.Callbacks.Count > 0);
         }
     }
 }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiContact.cs b/src/Microsoft.OpenApi/Models/OpenApiContact.cs
index e8f216fa3..2e92320a0 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiContact.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiContact.cs
@@ -12,7 +12,7 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Contact Object.
     /// </summary>
-    public class OpenApiContact
+    public class OpenApiContact : IOpenApiExtension
     {
         /// <summary>
         /// The identifying name of the contact person/organization.
@@ -33,6 +33,6 @@ public class OpenApiContact
         /// <summary>
         /// This object MAY be extended with Specification Extensions.
         /// </summary>
-        public Dictionary<string, IOpenApiExtension> Extensions { get; set; } = new Dictionary<string, IOpenApiExtension>();
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; } = new Dictionary<string, IOpenApiAny>();
     }
 }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiDocument.cs b/src/Microsoft.OpenApi/Models/OpenApiDocument.cs
index 97a728641..606801d9b 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiDocument.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiDocument.cs
@@ -13,7 +13,7 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Describes an Open API Document. See: https://swagger.io/specification
     /// </summary>
-    public class OpenApiDocument
+    public class OpenApiDocument : IOpenApiExtension
     {
         string version;
         public string Version { get { return version; }
@@ -29,13 +29,13 @@ public class OpenApiDocument
 
 
         public OpenApiInfo Info { get; set; } = new OpenApiInfo();
-        public List<OpenApiServer> Servers { get; set; } = new List<OpenApiServer>();
-        public List<OpenApiSecurityRequirement> SecurityRequirements { get; set; }
+        public IList<OpenApiServer> Servers { get; set; } = new List<OpenApiServer>();
+        public IList<OpenApiSecurityRequirement> SecurityRequirements { get; set; }
         public OpenApiPaths Paths { get; set; } = new OpenApiPaths();
         public OpenApiComponents Components { get; set; } = new OpenApiComponents();
-        public List<OpenApiTag> Tags { get; set; } = new List<OpenApiTag>();
+        public IList<OpenApiTag> Tags { get; set; } = new List<OpenApiTag>();
         public OpenApiExternalDocs ExternalDocs { get; set; } = new OpenApiExternalDocs();
-        public Dictionary<string, IOpenApiExtension> Extensions { get; set; } = new Dictionary<string, IOpenApiExtension>();
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
 
         private static Regex versionRegex = new Regex(@"\d+\.\d+\.\d+");
 
@@ -45,6 +45,5 @@ public void CreatePath(string key, Action<OpenApiPathItem> configure)
             configure(pathItem);
             Paths.Add(key, pathItem);
         }
-
     }
 }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiExample.cs b/src/Microsoft.OpenApi/Models/OpenApiExample.cs
index 12604ba7f..7f2c0b092 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiExample.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiExample.cs
@@ -11,7 +11,7 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Example Object.
     /// </summary>
-    public class OpenApiExample : IReference
+    public class OpenApiExample : IOpenApiReference, IOpenApiExtension
     {
         /// <summary>
         /// Short description for the example.
@@ -31,7 +31,7 @@ public class OpenApiExample : IReference
         /// <summary>
         /// This object MAY be extended with Specification Extensions.
         /// </summary>
-        public Dictionary<string, IOpenApiExtension> Extensions { get; set; } = new Dictionary<string, IOpenApiExtension>();
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
 
         public OpenApiReference Pointer
         {
diff --git a/src/Microsoft.OpenApi/Models/OpenApiExternalDocs.cs b/src/Microsoft.OpenApi/Models/OpenApiExternalDocs.cs
index d4219fbf9..7095f8602 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiExternalDocs.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiExternalDocs.cs
@@ -5,13 +5,14 @@
 //---------------------------------------------------------------------
 
 using System;
+using System.Collections.Generic;
 
 namespace Microsoft.OpenApi
 {
     /// <summary>
     /// ExternalDocs object.
     /// </summary>
-    public class OpenApiExternalDocs
+    public class OpenApiExternalDocs : IOpenApiExtension
     {
         /// <summary>
         /// REQUIRED.The URL for the target documentation. Value MUST be in the format of a URL.
@@ -22,5 +23,10 @@ public class OpenApiExternalDocs
         /// A short description of the target documentation.
         /// </summary>
         public Uri Url { get; set; }
+
+        /// <summary>
+        /// This object MAY be extended with Specification Extensions.
+        /// </summary>
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
     }
 }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiHeader.cs b/src/Microsoft.OpenApi/Models/OpenApiHeader.cs
index 3d6aaa354..8423d3db0 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiHeader.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiHeader.cs
@@ -12,7 +12,7 @@ namespace Microsoft.OpenApi
     /// Header Object.
     /// The Header Object follows the structure of the Parameter Object 
     /// </summary>
-    public class OpenApiHeader : IReference
+    public class OpenApiHeader : IOpenApiReference, IOpenApiExtension
     {
         public OpenApiReference Pointer { get; set; }
         public string Description { get; set; }
@@ -24,9 +24,9 @@ public class OpenApiHeader : IReference
         public bool AllowReserved { get; set; }
         public OpenApiSchema Schema { get; set; }
         public string Example { get; set; }
-        public List<OpenApiExample> Examples { get; set; }
-        public Dictionary<string, OpenApiMediaType> Content { get; set; }
+        public IList<OpenApiExample> Examples { get; set; }
+        public IDictionary<string, OpenApiMediaType> Content { get; set; }
 
-        public Dictionary<string, IOpenApiExtension> Extensions { get; set; } = new Dictionary<string, IOpenApiExtension>();
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
     }
 }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiInfo.cs b/src/Microsoft.OpenApi/Models/OpenApiInfo.cs
index d2189fb01..1936b8b54 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiInfo.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiInfo.cs
@@ -13,7 +13,7 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Open API Info Object, it provides the metadata about the Open API.
     /// </summary>
-    public class OpenApiInfo
+    public class OpenApiInfo : IOpenApiExtension
     {
         /// <summary>
         /// REQUIRED. The title of the application.
@@ -60,7 +60,7 @@ public string TermsOfService
         /// <summary>
         /// This object MAY be extended with Specification Extensions.
         /// </summary>
-        public Dictionary<string, IOpenApiExtension> Extensions { get; set; } = new Dictionary<string, IOpenApiExtension>();
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; } = new Dictionary<string, IOpenApiAny>();
 
         private static Regex versionRegex = new Regex(@"\d+\.\d+\.\d+");
     }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiLicense.cs b/src/Microsoft.OpenApi/Models/OpenApiLicense.cs
index 4eb4f6ee6..be280f2f3 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiLicense.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiLicense.cs
@@ -12,7 +12,7 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// License Object.
     /// </summary>
-    public class OpenApiLicense
+    public class OpenApiLicense : IOpenApiExtension
     {
         // <summary>
         /// REQUIRED.The license name used for the API.
@@ -27,6 +27,6 @@ public class OpenApiLicense
         /// <summary>
         /// This object MAY be extended with Specification Extensions.
         /// </summary>
-        public Dictionary<string, IOpenApiExtension> Extensions { get; set; } = new Dictionary<string, IOpenApiExtension>();
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; } = new Dictionary<string, IOpenApiAny>();
     }
 }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiLink.cs b/src/Microsoft.OpenApi/Models/OpenApiLink.cs
index 2f80f21b7..acef64ef2 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiLink.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiLink.cs
@@ -11,7 +11,7 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Link Object.
     /// </summary>
-    public class OpenApiLink :  IReference
+    public class OpenApiLink :  IOpenApiReference, IOpenApiExtension
     {
         public string Href { get; set; }
         public string OperationId { get; set; }
@@ -19,11 +19,9 @@ public class OpenApiLink :  IReference
         public RuntimeExpression RequestBody { get; set; }
 
         public string Description { get; set; }
-        public Dictionary<string, string> Extensions { get; set; }
-
-        public OpenApiReference Pointer { get; set; }
 
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
 
-        
+        public OpenApiReference Pointer { get; set; }
     }
 }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiMediaType.cs b/src/Microsoft.OpenApi/Models/OpenApiMediaType.cs
index ede7c0df7..fcf6aa7c3 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiMediaType.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiMediaType.cs
@@ -11,12 +11,12 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Media Type Object.
     /// </summary>
-    public class OpenApiMediaType
+    public class OpenApiMediaType : IOpenApiExtension
     {
         public OpenApiSchema Schema { get; set; }
-        public Dictionary<string, OpenApiExample> Examples { get; set; }
+        public IDictionary<string, OpenApiExample> Examples { get; set; }
         public string Example { get; set; }
 
-        public Dictionary<string, string> Extensions { get; set; }
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
     }
 }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiOperation.cs b/src/Microsoft.OpenApi/Models/OpenApiOperation.cs
index 622e0995a..11b01de2b 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiOperation.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiOperation.cs
@@ -12,23 +12,23 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Operation Object.
     /// </summary>
-    public class OpenApiOperation
+    public class OpenApiOperation : IOpenApiExtension
     {
-        public List<OpenApiTag> Tags { get; set; } = new List<OpenApiTag>();
+        public IList<OpenApiTag> Tags { get; set; } = new List<OpenApiTag>();
         public string Summary { get; set; }
         public string Description { get; set; }
         public OpenApiExternalDocs ExternalDocs { get; set; } 
         public string OperationId { get; set; }
-        public List<OpenApiParameter> Parameters { get; set; } = new List<OpenApiParameter>();
+        public IList<OpenApiParameter> Parameters { get; set; } = new List<OpenApiParameter>();
         public OpenApiRequestBody RequestBody { get; set; }
-        public Dictionary<string, OpenApiResponse> Responses { get; set; } = new Dictionary<string, OpenApiResponse>();
-        public Dictionary<string, OpenApiCallback> Callbacks { get; set; } = new Dictionary<string, OpenApiCallback>();
+        public IDictionary<string, OpenApiResponse> Responses { get; set; } = new Dictionary<string, OpenApiResponse>();
+        public IDictionary<string, OpenApiCallback> Callbacks { get; set; } = new Dictionary<string, OpenApiCallback>();
 
         public const bool DeprecatedDefault = false;
         public bool Deprecated { get; set; } = DeprecatedDefault;
-        public List<OpenApiSecurityRequirement> Security { get; set; } = new List<OpenApiSecurityRequirement>();
-        public List<OpenApiServer> Servers { get; set; } = new List<OpenApiServer>();
-        public Dictionary<string, IOpenApiExtension> Extensions { get; set; } = new Dictionary<string, IOpenApiExtension>();
+        public IList<OpenApiSecurityRequirement> Security { get; set; } = new List<OpenApiSecurityRequirement>();
+        public IList<OpenApiServer> Servers { get; set; } = new List<OpenApiServer>();
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
 
         public void CreateResponse(string key, Action<OpenApiResponse> configure)
         {
diff --git a/src/Microsoft.OpenApi/Models/OpenApiParameter.cs b/src/Microsoft.OpenApi/Models/OpenApiParameter.cs
index 55a24b141..474a34fc3 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiParameter.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiParameter.cs
@@ -19,7 +19,7 @@ public enum InEnum
     /// <summary>
     /// Parameter Object.
     /// </summary>
-    public class OpenApiParameter : IReference
+    public class OpenApiParameter : IOpenApiReference, IOpenApiExtension
     {
         public OpenApiReference Pointer { get; set; }
         public string Name { get; set; }
@@ -56,11 +56,9 @@ public bool Required
         public bool Explode { get; set; }
         public bool AllowReserved { get; set; }
         public OpenApiSchema Schema { get; set; }
-        public List<OpenApiExample> Examples { get; set; } = new List<OpenApiExample>();
+        public IList<OpenApiExample> Examples { get; set; } = new List<OpenApiExample>();
         public string Example { get; set; }
-        public Dictionary<string, OpenApiMediaType> Content { get; set; }
-        public Dictionary<string, IOpenApiExtension> Extensions { get; set; } = new Dictionary<string, IOpenApiExtension>();
-
-        
+        public IDictionary<string, OpenApiMediaType> Content { get; set; }
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
     }
-    }
\ No newline at end of file
+}
diff --git a/src/Microsoft.OpenApi/Models/OpenApiPathItem.cs b/src/Microsoft.OpenApi/Models/OpenApiPathItem.cs
index 71d26ef56..0d8803790 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiPathItem.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiPathItem.cs
@@ -13,17 +13,17 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Path Item Object: to describe the operations available on a single path.
     /// </summary>
-    public class OpenApiPathItem
+    public class OpenApiPathItem : IOpenApiExtension
     {
         public string Summary { get; set; }
         public string Description { get; set; }
 
-        public IReadOnlyDictionary<string, OpenApiOperation> Operations { get { return operations; } }
+        public IDictionary<string, OpenApiOperation> Operations { get { return operations; } }
         private Dictionary<string, OpenApiOperation> operations = new Dictionary<string, OpenApiOperation>();
 
-        public List<OpenApiServer> Servers { get; set; } = new List<OpenApiServer>();
-        public List<OpenApiParameter> Parameters { get; set; } = new List<OpenApiParameter>();
-        public Dictionary<string, IOpenApiExtension> Extensions { get; set; } = new Dictionary<string, IOpenApiExtension>();
+        public IList<OpenApiServer> Servers { get; set; } = new List<OpenApiServer>();
+        public IList<OpenApiParameter> Parameters { get; set; } = new List<OpenApiParameter>();
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
 
         public void CreateOperation(OperationType operationType, Action<OpenApiOperation> configure)
         {
diff --git a/src/Microsoft.OpenApi/Models/OpenApiPaths.cs b/src/Microsoft.OpenApi/Models/OpenApiPaths.cs
index a9b2d5387..61886d2be 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiPaths.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiPaths.cs
@@ -12,12 +12,12 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Paths object.
     /// </summary>
-    public class OpenApiPaths : IDictionary<string, OpenApiPathItem>
+    public class OpenApiPaths : IDictionary<string, OpenApiPathItem>, IOpenApiExtension
     {
         public OpenApiPathItem this[string key] { get => this.PathItems[key]; set => this.PathItems[key] = value; }
 
         private IDictionary<string, OpenApiPathItem> PathItems { get; set; } = new Dictionary<string, OpenApiPathItem>();
-        public Dictionary<string, IOpenApiExtension> Extensions { get; set; } = new Dictionary<string, IOpenApiExtension>();
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
 
         public ICollection<string> Keys => this.PathItems.Keys;
 
diff --git a/src/Microsoft.OpenApi/Models/OpenApiReference.cs b/src/Microsoft.OpenApi/Models/OpenApiReference.cs
index 64fa8ed23..bd724b357 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiReference.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiReference.cs
@@ -22,7 +22,7 @@ public enum ReferenceType
         Tags
     }
 
-    public class OpenApiReference
+    public class OpenApiReference : IOpenApiElement
     {
         public ReferenceType ReferenceType { get; set; }
         public string TypeName { get; set; }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiRequestBody.cs b/src/Microsoft.OpenApi/Models/OpenApiRequestBody.cs
index 2c8c6e072..b7ed7dafa 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiRequestBody.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiRequestBody.cs
@@ -12,13 +12,13 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Request Body Object
     /// </summary>
-    public class OpenApiRequestBody : IReference
+    public class OpenApiRequestBody : IOpenApiReference, IOpenApiExtension
     {
         public OpenApiReference Pointer { get; set; }
 
         public string Description { get; set; }
         public Boolean Required { get; set; }
-        public Dictionary<string, OpenApiMediaType> Content { get; set; }
-        public Dictionary<string,string> Extensions { get; set; }
+        public IDictionary<string, OpenApiMediaType> Content { get; set; }
+        public IDictionary<string,IOpenApiAny> Extensions { get; set; }
     }
 }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiResponse.cs b/src/Microsoft.OpenApi/Models/OpenApiResponse.cs
index 8ee0faed3..707717391 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiResponse.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiResponse.cs
@@ -12,13 +12,13 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Response object.
     /// </summary>
-    public class OpenApiResponse : IReference
+    public class OpenApiResponse : IOpenApiReference, IOpenApiExtension
     {
         public string Description { get; set; }
-        public Dictionary<string, OpenApiMediaType> Content { get; set; }
-        public Dictionary<string, OpenApiHeader> Headers { get; set; }
-        public Dictionary<string, OpenApiLink> Links { get; set; }
-        public Dictionary<string, IOpenApiExtension> Extensions { get; set; }
+        public IDictionary<string, OpenApiMediaType> Content { get; set; }
+        public IDictionary<string, OpenApiHeader> Headers { get; set; }
+        public IDictionary<string, OpenApiLink> Links { get; set; }
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
 
         public OpenApiReference Pointer
         {
diff --git a/src/Microsoft.OpenApi/Models/OpenApiSchema.cs b/src/Microsoft.OpenApi/Models/OpenApiSchema.cs
index 44eadb57e..4f1eb9d1d 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiSchema.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiSchema.cs
@@ -11,7 +11,7 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Schema Object.
     /// </summary>
-    public class OpenApiSchema : IReference
+    public class OpenApiSchema : IOpenApiReference, IOpenApiExtension
     {
         public string Title { get; set; }
         public string Type { get; set; }
@@ -28,28 +28,36 @@ public class OpenApiSchema : IReference
         public string Default { get; set; }
         public bool ReadOnly { get; set; }
         public bool WriteOnly { get; set; }
-        public List<OpenApiSchema> AllOf { get; set; }
-        public List<OpenApiSchema> OneOf { get; set; }
-        public List<OpenApiSchema> AnyOf { get; set; }
+        public IList<OpenApiSchema> AllOf { get; set; }
+        public IList<OpenApiSchema> OneOf { get; set; }
+        public IList<OpenApiSchema> AnyOf { get; set; }
         public OpenApiSchema Not { get; set; }
         public string[] Required { get; set; }
         public OpenApiSchema Items { get; set; }
         public int? MaxItems { get; set; }
         public int? MinItems { get; set; }
         public bool UniqueItems { get; set; }
-        public Dictionary<string,OpenApiSchema> Properties { get; set; }
+        public IDictionary<string,OpenApiSchema> Properties { get; set; }
         public int? MaxProperties { get; set; }
         public int? MinProperties { get; set; }
         public bool AdditionalPropertiesAllowed { get; set; }
         public OpenApiSchema AdditionalProperties { get; set; }
 
         public string Example { get; set; }
-        public List<string> Enum { get; set; } = new List<string>();
+        public IList<string> Enum { get; set; } = new List<string>();
         public bool Nullable { get; set; }
         public OpenApiExternalDocs ExternalDocs { get; set; }
         public bool Deprecated { get; set; }
 
-        public Dictionary<string, IOpenApiExtension> Extensions { get; set; } = new Dictionary<string, IOpenApiExtension>();
+        /// <summary>
+        /// Adds additional metadata to describe the XML representation of this property.
+        /// </summary>
+        public OpenApiXml Xml { get; set; }
+
+        /// <summary>
+        /// Specification Extensions.
+        /// </summary>
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
 
         public OpenApiReference Pointer
         {
diff --git a/src/Microsoft.OpenApi/Models/OpenApiSecurityRequirement.cs b/src/Microsoft.OpenApi/Models/OpenApiSecurityRequirement.cs
index abb6b4ba2..3273fe2ea 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiSecurityRequirement.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiSecurityRequirement.cs
@@ -11,7 +11,7 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Security Requirement Object
     /// </summary>
-    public class OpenApiSecurityRequirement
+    public class OpenApiSecurityRequirement : IOpenApiElement
     {
         public Dictionary<OpenApiSecurityScheme, List<string>> Schemes { get; set; } = new Dictionary<OpenApiSecurityScheme, List<string>>();
     }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiSecurityScheme.cs b/src/Microsoft.OpenApi/Models/OpenApiSecurityScheme.cs
index cc32aa0be..0bdbd4769 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiSecurityScheme.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiSecurityScheme.cs
@@ -12,7 +12,7 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Security Scheme Object.
     /// </summary>
-    public class OpenApiSecurityScheme : IReference
+    public class OpenApiSecurityScheme : IOpenApiReference, IOpenApiExtension
     {
         public string Key { get; set; }
         public string Type { get; set; }
@@ -25,9 +25,9 @@ public class OpenApiSecurityScheme : IReference
         public string Flow { get; set; }
         public Uri AuthorizationUrl { get; set; }
         public Uri TokenUrl { get; set; }
-        public Dictionary<string,string> Scopes { get; set; }
+        public IDictionary<string,string> Scopes { get; set; }
 
-        public Dictionary<string, IOpenApiExtension> Extensions { get; set; } = new Dictionary<string, IOpenApiExtension>();
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
 
         public OpenApiReference Pointer
         {
diff --git a/src/Microsoft.OpenApi/Models/OpenApiServer.cs b/src/Microsoft.OpenApi/Models/OpenApiServer.cs
index f4be8d780..df2bf585a 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiServer.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiServer.cs
@@ -11,12 +11,12 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Server Object: an object representing a Server.
     /// </summary>
-    public class OpenApiServer
+    public class OpenApiServer : IOpenApiExtension
     {
         public string Description { get; set; }
         public string Url { get; set; }
-        public Dictionary<string, OpenApiServerVariable> Variables { get; set; } = new Dictionary<string, OpenApiServerVariable>();
+        public IDictionary<string, OpenApiServerVariable> Variables { get; set; } = new Dictionary<string, OpenApiServerVariable>();
 
-        public Dictionary<string, string> Extensions { get; set; } = new Dictionary<string, string>();
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
     }
 }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiServerVariable.cs b/src/Microsoft.OpenApi/Models/OpenApiServerVariable.cs
index 471e622c1..d26f5e23d 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiServerVariable.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiServerVariable.cs
@@ -11,12 +11,12 @@ namespace Microsoft.OpenApi
     /// <summary>
     /// Server Variable Object.
     /// </summary>
-    public class OpenApiServerVariable
+    public class OpenApiServerVariable : IOpenApiExtension
     {
         public string Description { get; set; }
         public string Default { get; set; }
         public List<string> Enum { get; set; } = new List<string>();
 
-        public Dictionary<string, string> Extensions { get; set; } = new Dictionary<string, string>();
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
     }
 }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiTag.cs b/src/Microsoft.OpenApi/Models/OpenApiTag.cs
index 090db16a4..d671ae1e9 100644
--- a/src/Microsoft.OpenApi/Models/OpenApiTag.cs
+++ b/src/Microsoft.OpenApi/Models/OpenApiTag.cs
@@ -4,12 +4,14 @@
 // </copyright>
 //---------------------------------------------------------------------
 
+using System.Collections.Generic;
+
 namespace Microsoft.OpenApi
 {
     /// <summary>
     /// Tag Object.
     /// </summary>
-    public class OpenApiTag : IReference
+    public class OpenApiTag : IOpenApiReference, IOpenApiExtension
     {
         /// <summary>
         /// The name of the tag.
@@ -26,7 +28,12 @@ public class OpenApiTag : IReference
         /// </summary>
         public OpenApiExternalDocs ExternalDocs { get; set; }
 
-        OpenApiReference IReference.Pointer
+        /// <summary>
+        /// This object MAY be extended with Specification Extensions.
+        /// </summary>
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
+
+        OpenApiReference IOpenApiReference.Pointer
         {
             get; set;
         }
diff --git a/src/Microsoft.OpenApi/Models/OpenApiXml.cs b/src/Microsoft.OpenApi/Models/OpenApiXml.cs
new file mode 100644
index 000000000..a593b60c4
--- /dev/null
+++ b/src/Microsoft.OpenApi/Models/OpenApiXml.cs
@@ -0,0 +1,49 @@
+//---------------------------------------------------------------------
+// <copyright file="OpenApiXml.cs" company="Microsoft">
+//      Copyright (C) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
+// </copyright>
+//---------------------------------------------------------------------
+
+using System;
+using System.Collections.Generic;
+
+namespace Microsoft.OpenApi
+{
+    /// <summary>
+    /// XML Object.
+    /// </summary>
+    public class OpenApiXml : IOpenApiExtension
+    {
+        /// <summary>
+        /// Replaces the name of the element/attribute used for the described schema property.
+        /// </summary>
+        public string Name { get; set; }
+
+        /// <summary>
+        /// The URI of the namespace definition.
+        /// </summary>
+        public Uri Namespace { get; set; }
+
+        /// <summary>
+        /// The prefix to be used for the name
+        /// </summary>
+        public string Prefix { get; set; }
+
+        /// <summary>
+        /// Declares whether the property definition translates to an attribute instead of an element.
+        /// Default value is false.
+        /// </summary>
+        public bool Attribute { get; set; }
+
+        /// <summary>
+        /// Signifies whether the array is wrapped.
+        /// Default value is false.
+        /// </summary>
+        public bool Wrapped { get; set; }
+
+        /// <summary>
+        /// Specification Extensions.
+        /// </summary>
+        public IDictionary<string, IOpenApiAny> Extensions { get; set; }
+    }
+}
diff --git a/src/Microsoft.OpenApi/Sevices/OpenApiVisitorBase.cs b/src/Microsoft.OpenApi/Sevices/OpenApiVisitorBase.cs
index da0aa2ed7..cbd9fb8d1 100644
--- a/src/Microsoft.OpenApi/Sevices/OpenApiVisitorBase.cs
+++ b/src/Microsoft.OpenApi/Sevices/OpenApiVisitorBase.cs
@@ -12,23 +12,23 @@ public abstract class OpenApiVisitorBase
     {
         public virtual void Visit(OpenApiDocument doc) { }
         public virtual void Visit(OpenApiInfo info) { }
-        public virtual void Visit(List<OpenApiServer> servers) { }
+        public virtual void Visit(IList<OpenApiServer> servers) { }
         public virtual void Visit(OpenApiServer server) { }
         public virtual void Visit(OpenApiPaths paths) { }
         public virtual void Visit(OpenApiPathItem pathItem) { }
         public virtual void Visit(OpenApiServerVariable serverVariable) { }
-        public virtual void Visit(IReadOnlyDictionary<string,OpenApiOperation> operations) { }
+        public virtual void Visit(IDictionary<string,OpenApiOperation> operations) { }
         public virtual void Visit(OpenApiOperation operation) { }
-        public virtual void Visit(List<OpenApiParameter> parameters) { }
+        public virtual void Visit(IList<OpenApiParameter> parameters) { }
         public virtual void Visit(OpenApiParameter parameter) { }
         public virtual void Visit(OpenApiRequestBody requestBody) { }
-        public virtual void Visit(IReadOnlyDictionary<string, OpenApiResponse> responses) { }
+        public virtual void Visit(IDictionary<string, OpenApiResponse> responses) { }
         public virtual void Visit(OpenApiResponse response) { }
-        public virtual void Visit(Dictionary<string,OpenApiMediaType> content) { }
+        public virtual void Visit(IDictionary<string,OpenApiMediaType> content) { }
         public virtual void Visit(OpenApiMediaType mediaType) { }
-        public virtual void Visit(Dictionary<string, OpenApiExample> example) { }
+        public virtual void Visit(IDictionary<string, OpenApiExample> example) { }
         public virtual void Visit(OpenApiSchema example) { }
-        public virtual void Visit(Dictionary<string, OpenApiLink> links) { }
+        public virtual void Visit(IDictionary<string, OpenApiLink> links) { }
         public virtual void Visit(OpenApiLink link) { }
     }
 }
diff --git a/src/Microsoft.OpenApi/Sevices/OpenApiWalker.cs b/src/Microsoft.OpenApi/Sevices/OpenApiWalker.cs
index 9533e6e18..de513e5aa 100644
--- a/src/Microsoft.OpenApi/Sevices/OpenApiWalker.cs
+++ b/src/Microsoft.OpenApi/Sevices/OpenApiWalker.cs
@@ -80,7 +80,7 @@ public void Walk(OpenApiDocument doc)
             }
         }
 
-        private void WalkContent(Dictionary<string, OpenApiMediaType> content)
+        private void WalkContent(IDictionary<string, OpenApiMediaType> content)
         {
             if (content == null) return;
 
diff --git a/src/Microsoft.OpenApi/Writers/IReferenceExtensions.cs b/src/Microsoft.OpenApi/Writers/OpenApiReferenceWriterExtensions.cs
similarity index 65%
rename from src/Microsoft.OpenApi/Writers/IReferenceExtensions.cs
rename to src/Microsoft.OpenApi/Writers/OpenApiReferenceWriterExtensions.cs
index 65fd5541b..ca6721795 100644
--- a/src/Microsoft.OpenApi/Writers/IReferenceExtensions.cs
+++ b/src/Microsoft.OpenApi/Writers/OpenApiReferenceWriterExtensions.cs
@@ -1,26 +1,23 @@
 //---------------------------------------------------------------------
-// <copyright file="IReferenceExtensions.cs" company="Microsoft">
+// <copyright file="OpenApiReferenceWriterExtensions.cs" company="Microsoft">
 //      Copyright (C) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
 // </copyright>
 //---------------------------------------------------------------------
 
 namespace Microsoft.OpenApi.Writers
 {
-    using Microsoft.OpenApi;
-
-    public static class IReferenceExtensions
+    public static class OpenApiReferenceWriterExtensions
     {
-        public static bool IsReference(this IReference reference)
+        public static bool IsReference(this IOpenApiReference reference)
         {
             return reference.Pointer != null;
         }
 
-        public static void WriteRef(this IReference reference, IOpenApiWriter writer)
+        public static void WriteRef(this IOpenApiReference reference, IOpenApiWriter writer)
         {
             writer.WriteStartObject();
             writer.WriteStringProperty("$ref", reference.Pointer.ToString());
             writer.WriteEndObject();
         }
-
     }
 }
diff --git a/test/Microsoft.OpenApi.Readers.Tests/DownGradeTests.cs b/test/Microsoft.OpenApi.Readers.Tests/DownGradeTests.cs
index 2602f58c8..ad4fa0538 100644
--- a/test/Microsoft.OpenApi.Readers.Tests/DownGradeTests.cs
+++ b/test/Microsoft.OpenApi.Readers.Tests/DownGradeTests.cs
@@ -116,7 +116,6 @@ public void TestRequestBody()
             Assert.Equal("body", (string)bodyparam["in"]);
             Assert.Equal("string", (string)bodyparam["schema"]["type"]);
             Assert.Equal("100", (string)bodyparam["schema"]["maxLength"]);
-
         }
 
         [Fact]
diff --git a/test/Microsoft.OpenApi.Readers.Tests/InfoTests.cs b/test/Microsoft.OpenApi.Readers.Tests/InfoTests.cs
index ebf977a85..24b85002a 100644
--- a/test/Microsoft.OpenApi.Readers.Tests/InfoTests.cs
+++ b/test/Microsoft.OpenApi.Readers.Tests/InfoTests.cs
@@ -25,7 +25,6 @@ public void CheckPetStoreApiInfo()
         [Fact]
         public void ParseCompleteHeaderOpenApi()
         {
-
             var stream = this.GetType().Assembly.GetManifestResourceStream(typeof(InfoTests), "Samples.CompleteHeader.yaml");
 
             var openApiDoc = new OpenApiStreamReader().Read(stream, out var context);