/// <inheridoc />
        public override void WriteObject(object graph, Type type, ODataMessageWriter messageWriter, ODataSerializerContext writeContext)
        {
            if (messageWriter == null)
            {
                throw Error.ArgumentNull("messageWriter");
            }

            if (writeContext == null)
            {
                throw Error.ArgumentNull("writeContext");
            }

            if (graph != null)
            {
                ODataEntityReferenceLinks entityReferenceLinks = graph as ODataEntityReferenceLinks;
                if (entityReferenceLinks == null)
                {
                    IEnumerable<Uri> uris = graph as IEnumerable<Uri>;
                    if (uris == null)
                    {
                        throw new SerializationException(Error.Format(SRResources.CannotWriteType, GetType().Name, graph.GetType().FullName));
                    }

                    entityReferenceLinks = new ODataEntityReferenceLinks
                    {
                        Links = uris.Select(uri => new ODataEntityReferenceLink { Url = uri })
                    };
                }

                messageWriter.WriteEntityReferenceLinks(entityReferenceLinks);
            }
        }

        public void ReadJsonLight()
        {
            // Arrange
            var deserializer = new ODataEntityReferenceLinkDeserializer();
            MockODataRequestMessage requestMessage = new MockODataRequestMessage();
            ODataMessageWriterSettings writerSettings = new ODataMessageWriterSettings();
            writerSettings.SetContentType(ODataFormat.Json);
            IEdmModel model = CreateModel();
            ODataMessageWriter messageWriter = new ODataMessageWriter(requestMessage, writerSettings, model);
            messageWriter.WriteEntityReferenceLink(new ODataEntityReferenceLink { Url = new Uri("http://localhost/samplelink") });
            ODataMessageReader messageReader = new ODataMessageReader(new MockODataRequestMessage(requestMessage),
                new ODataMessageReaderSettings(), model);

            IEdmNavigationProperty navigationProperty = GetNavigationProperty(model);

            ODataDeserializerContext context = new ODataDeserializerContext
            {
                Request = new HttpRequestMessage(),
                Path = new ODataPath(new NavigationPathSegment(navigationProperty))
            };

            // Act
            Uri uri = deserializer.Read(messageReader, typeof(Uri), context) as Uri;

            // Assert
            Assert.NotNull(uri);
            Assert.Equal("http://localhost/samplelink", uri.AbsoluteUri);
        }

        /// <inheritdoc />
        public override void WriteObject(object graph, Type type, ODataMessageWriter messageWriter,
            ODataSerializerContext writeContext)
        {
            if (messageWriter == null)
            {
                throw Error.ArgumentNull("messageWriter");
            }

            if (writeContext == null)
            {
                throw Error.ArgumentNull("writeContext");
            }

            IEdmNavigationSource navigationSource = writeContext.NavigationSource;
            if (navigationSource == null)
            {
                throw new SerializationException(SRResources.NavigationSourceMissingDuringSerialization);
            }

            var path = writeContext.Path;
            if (path == null)
            {
                throw new SerializationException(SRResources.ODataPathMissing);
            }

            ODataWriter writer = messageWriter.CreateODataEntryWriter(navigationSource, path.EdmType as IEdmEntityType);
            WriteObjectInline(graph, navigationSource.EntityType().ToEdmTypeReference(isNullable: false), writer, writeContext);
        }

        /// <summary>
        /// Writes the entity result to the response message.
        /// </summary>
        /// <param name="graph">The entity result to write.</param>
        /// <param name="type">The type of the entity.</param>
        /// <param name="messageWriter">The message writer.</param>
        /// <param name="writeContext">The writing context.</param>
        public override void WriteObject(
            object graph,
            Type type,
            ODataMessageWriter messageWriter,
            ODataSerializerContext writeContext)
        {
            RawResult rawResult = graph as RawResult;
            if (rawResult != null)
            {
                graph = rawResult.Result;
                type = rawResult.Type;
            }

            if (writeContext != null)
            {
                graph = RestierPrimitiveSerializer.ConvertToPayloadValue(graph, writeContext);
            }

            if (graph == null)
            {
                // This is to make ODataRawValueSerializer happily serialize null value.
                graph = string.Empty;
            }

            base.WriteObject(graph, type, messageWriter, writeContext);
        }

        /// <inheritdoc/>
        public override void WriteObject(object graph, ODataMessageWriter messageWriter, ODataSerializerContext writeContext)
        {
            if (messageWriter == null)
            {
                throw Error.ArgumentNull("messageWriter");
            }

            if (writeContext == null)
            {
                throw Error.ArgumentNull("writeContext");
            }

            ODataCollectionWriter writer = messageWriter.CreateODataCollectionWriter();
            writer.WriteStart(
                new ODataCollectionStart
                {
                    Name = writeContext.RootElementName
                });

            ODataProperty property = CreateProperty(graph, writeContext.RootElementName, writeContext);
            if (property != null)
            {
                ODataCollectionValue collectionValue = property.Value as ODataCollectionValue;

                foreach (object item in collectionValue.Items)
                {
                    writer.WriteItem(item);
                }

                writer.WriteEnd();
                writer.Flush();
            }
        }

        public void WriteCompletedAsyncResponse()
        {
            var asyncWriter = this.TestInit();

            var innerMessage = asyncWriter.CreateResponseMessage();
            innerMessage.StatusCode = 200;
            innerMessage.SetHeader("Content-Type", "application/json");

            var settings = new ODataMessageWriterSettings();
            settings.SetServiceDocumentUri(new Uri(ServiceDocumentUri));
            settings.DisableMessageStreamDisposal = true;

            using (var innerMessageWriter = new ODataMessageWriter(innerMessage, settings, this.userModel))
            {
                var entryWriter = innerMessageWriter.CreateODataEntryWriter(singleton, testType);
                var entry = new ODataEntry() {TypeName = "NS.Test", Properties = new[] {new ODataProperty() {Name = "Id", Value = 1}}};
                entryWriter.WriteStart(entry);
                entryWriter.WriteEnd();
            }

            asyncWriter.Flush();

            var payload = this.TestFinish();
            Assert.Equal("HTTP/1.1 200 OK\r\nContent-Type: application/json\r\nOData-Version: 4.0\r\n\r\n{\"@odata.context\":\"http://host/service/$metadata#MySingleton\",\"Id\":1}", payload);
        }

        /// <inheritdoc />
        public override void WriteObject(object graph, Type type, ODataMessageWriter messageWriter, ODataSerializerContext writeContext)
        {
            if (messageWriter == null)
            {
                throw Error.ArgumentNull("messageWriter");
            }

            if (writeContext == null)
            {
                throw Error.ArgumentNull("writeContext");
            }

            IEdmEntitySetBase entitySet = writeContext.NavigationSource as IEdmEntitySetBase;
            if (entitySet == null)
            {
                throw new SerializationException(SRResources.EntitySetMissingDuringSerialization);
            }

            IEdmTypeReference feedType = writeContext.GetEdmType(graph, type);
            Contract.Assert(feedType != null);

            IEdmEntityTypeReference entityType = GetEntityType(feedType);
            ODataWriter writer = messageWriter.CreateODataFeedWriter(entitySet, entityType.EntityDefinition());
            WriteObjectInline(graph, feedType, writer, writeContext);
        }

        /// <summary>Initializes a new NonEntitySerializer instance.</summary>
        /// <param name="requestDescription">Description of request.</param>
        /// <param name="absoluteServiceUri">Base URI from which resources should be resolved.</param>
        /// <param name="service">Service with configuration and provider from which metadata should be gathered.</param>
        /// <param name="messageWriter">ODataMessageWriter instance which needs to be used to write the response.</param>
        internal NonEntitySerializer(RequestDescription requestDescription, Uri absoluteServiceUri, IDataService service, ODataMessageWriter messageWriter)
            : base(requestDescription, absoluteServiceUri, service, null)
        {
            Debug.Assert(messageWriter != null, "messageWriter != null");

            this.writer = messageWriter;
        }

        public override void WriteObject(object graph, ODataMessageWriter messageWriter, ODataSerializerContext writeContext)
        {
            if (messageWriter == null)
            {
                throw Error.ArgumentNull("messageWriter");
            }

            if (writeContext == null)
            {
                throw Error.ArgumentNull("writeContext");
            }

            IEdmEntitySet entitySet = writeContext.EntitySet;

            if (entitySet == null)
            {
                throw new SerializationException(SRResources.EntitySetMissingDuringSerialization);
            }

            // No null check; entity type is not required for successful serialization.
            IEdmEntityType entityType = _edmElementType;

            ODataWriter writer = messageWriter.CreateODataFeedWriter(entitySet, entityType);
            WriteObjectInline(graph, writer, writeContext);
            writer.Flush();
        }

 public void CreateCollectionWriterWithTypeDefinitionAsItemType()
 {
     var writer = new ODataMessageWriter(new DummyRequestMessage());
     var entityElementType = new EdmTypeDefinitionReference(new EdmTypeDefinition("NS", "Test", EdmPrimitiveTypeKind.Int32), false);
     var collectionWriter = writer.CreateODataCollectionWriter(entityElementType);
     Assert.IsNotNull(collectionWriter, "CreateODataCollectionWriter with type definition item type failed.");
 }

 public void CreateMessageWriterShouldSetAnnotationFilterWhenODataAnnotationIsSetOnPreferenceAppliedHeader()
 {
     IODataResponseMessage responseMessage = new InMemoryMessage();
     responseMessage.PreferenceAppliedHeader().AnnotationFilter = "*";
     ODataMessageWriter writer = new ODataMessageWriter(responseMessage, new ODataMessageWriterSettings());
     writer.Settings.ShouldIncludeAnnotation.Should().NotBeNull();
 }

 public void CreateCollectionWriterWithEnumAsItemType()
 {
     var writer = new ODataMessageWriter(new DummyRequestMessage());
     var entityElementType = new EdmEnumTypeReference(new EdmEnumType("FakeNS", "FakeEnum"), true);
     var collectionWriter = writer.CreateODataCollectionWriter(entityElementType);
     Assert.IsNotNull(collectionWriter, "CreateODataCollectionWriter with enum item type failed.");
 }

 public void CreateCollectionWriterWithEntityCollectionTypeShouldFail()
 {
     var writer = new ODataMessageWriter(new DummyRequestMessage());
     var entityElementType = new EdmEntityTypeReference(new EdmEntityType("Fake", "Fake"), true);
     Action createWriterWithEntityCollectionType = () => writer.CreateODataCollectionWriter(entityElementType);
     createWriterWithEntityCollectionType.ShouldThrow<ODataException>().WithMessage(Strings.ODataMessageWriter_NonCollectionType("Fake.Fake"));
 }

 public void CreateCollectionWriterWithoutTypeShouldPassForJsonLight()
 {
     var settings = new ODataMessageWriterSettings();
     settings.SetContentType(ODataFormat.Json);
     var writer = new ODataMessageWriter(new DummyRequestMessage(), settings, new EdmModel());
     writer.CreateODataCollectionWriter(null).Should().BeOfType<ODataJsonLightCollectionWriter>();
 }

        /// <inheritdoc/>
        public override Task WriteObjectAsync(object graph, Type type, ODataMessageWriter messageWriter, ODataSerializerContext writeContext)
        {
            if (messageWriter == null)
            {
                throw Error.ArgumentNull("messageWriter");
            }

            if (writeContext == null)
            {
                throw Error.ArgumentNull("writeContext");
            }

            if (graph != null)
            {
                ODataEntityReferenceLink entityReferenceLink = graph as ODataEntityReferenceLink;
                if (entityReferenceLink == null)
                {
                    Uri uri = graph as Uri;
                    if (uri == null)
                    {
                        throw new SerializationException(Error.Format(SRResources.CannotWriteType, GetType().Name, graph.GetType().FullName));
                    }

                    entityReferenceLink = new ODataEntityReferenceLink { Url = uri };
                }

                messageWriter.WriteEntityReferenceLink(entityReferenceLink);
            }

	        return Task.FromResult(true);
        }

        public void WriteMessageAsync_ResponseContainsContentId_IfHasContentIdInRequestChangeSet()
        {
            MemoryStream ms = new MemoryStream();
            HttpContent content = new StringContent(String.Empty, Encoding.UTF8, "multipart/mixed");
            content.Headers.ContentType.Parameters.Add(new NameValueHeaderValue("boundary", Guid.NewGuid().ToString()));
            IODataResponseMessage odataResponse = new ODataMessageWrapper(ms, content.Headers);
            var batchWriter = new ODataMessageWriter(odataResponse).CreateODataBatchWriter();
            HttpResponseMessage response = new HttpResponseMessage
            {
                Content = new StringContent("any", Encoding.UTF8, "text/example")
            };
            var request = new HttpRequestMessage();
            var contentId = Guid.NewGuid().ToString();
            request.SetODataContentId(contentId);
            response.RequestMessage = request;

            batchWriter.WriteStartBatch();
            batchWriter.WriteStartChangeset();
            ODataBatchResponseItem.WriteMessageAsync(batchWriter, response, CancellationToken.None).Wait();
            batchWriter.WriteEndChangeset();
            batchWriter.WriteEndBatch();

            ms.Position = 0;
            string result = new StreamReader(ms).ReadToEnd();

            Assert.Contains("any", result);
            Assert.Contains("text/example", result);
            Assert.Contains("Content-ID", result);
            Assert.Contains(contentId, result);
        }

        /// <summary>
        /// Determines the response format based on the results of content negotiation.
        /// </summary>
        /// <param name="payloadKind">The payload kind of the response.</param>
        /// <param name="acceptableMediaTypes">
        /// The acceptable media types used to determine the content type of the message.
        /// This is a comma separated list of content types as specified in RFC 2616, Section 14.1
        /// </param>
        /// <param name="acceptableCharSets">
        /// The acceptable charsets to use to the determine the encoding of the message.
        /// This is a comma separated list of charsets as specified in RFC 2616, Section 14.2
        /// </param>
        /// <returns>The format the response should use. </returns>
        internal ODataFormatWithParameters DetermineResponseFormat(ODataPayloadKind payloadKind, string acceptableMediaTypes, string acceptableCharSets)
        {
            Debug.Assert(payloadKind != ODataPayloadKind.Unsupported, "kind != ODataPayloadKind.Unsupported");

            ContentNegotiationResponseMessage responseMessage = new ContentNegotiationResponseMessage();

            ODataMessageWriterSettings settings = new ODataMessageWriterSettings { Version = this.responseVersion };
            settings.EnableAtomSupport();
            settings.SetContentType(acceptableMediaTypes, acceptableCharSets);

            try
            {
                using (ODataMessageWriter writer = new ODataMessageWriter(responseMessage, settings))
                {
                    ODataFormat format = ODataUtils.SetHeadersForPayload(writer, payloadKind);
                    return new ODataFormatWithParameters(format, responseMessage.ContentType);
                }
            }
            catch (ODataContentTypeException exception)
            {
                if (this.throwIfNoMatch)
                {
                    throw new DataServiceException(415, null, Microsoft.OData.Service.Strings.DataServiceException_UnsupportedMediaType, null, exception);
                }

                return null;
            }
        }

        public override void WriteObject(object graph, ODataMessageWriter messageWriter, ODataSerializerContext writeContext)
        {
            if (messageWriter == null)
            {
                throw Error.ArgumentNull("messageWriter");
            }

            if (writeContext == null)
            {
                throw Error.ArgumentNull("writeContext");
            }

            IEdmEntitySet entitySet = writeContext.EntitySet;

            if (entitySet == null)
            {
                throw new SerializationException(SRResources.EntitySetMissingDuringSerialization);
            }

            IEdmNavigationProperty navigationProperty = GetNavigationProperty(writeContext.Path);

            if (navigationProperty == null)
            {
                throw new SerializationException(SRResources.NavigationPropertyMissingDuringSerialization);
            }

            messageWriter.WriteEntityReferenceLink(new ODataEntityReferenceLink { Url = graph as Uri }, entitySet,
                navigationProperty);
        }

 public void WriteObject_ThrowsArgumentNull_WriteContext()
 {
     ODataMessageWriter messageWriter = new ODataMessageWriter(new Mock<IODataRequestMessage>().Object);
     Assert.ThrowsArgumentNull(
         () => _serializer.WriteObject(graph: new object(), messageWriter: messageWriter, writeContext: null),
         "writeContext");
 }

        public void WriteObject_WritesValueReturnedFrom_CreateODataCollectionValue()
        {
            // Arrange
            MemoryStream stream = new MemoryStream();
            IODataResponseMessage message = new ODataMessageWrapper(stream);
            ODataMessageWriterSettings settings = new ODataMessageWriterSettings()
            {
                ODataUri = new ODataUri { ServiceRoot = new Uri("http://any/") }
            };

            settings.SetContentType(ODataFormat.Json);

            ODataMessageWriter messageWriter = new ODataMessageWriter(message, settings);
            Mock<ODataCollectionSerializer> serializer = new Mock<ODataCollectionSerializer>(new DefaultODataSerializerProvider());
            ODataSerializerContext writeContext = new ODataSerializerContext { RootElementName = "CollectionName", Model = _model };
            IEnumerable enumerable = new object[0];
            ODataCollectionValue collectionValue = new ODataCollectionValue { TypeName = "NS.Name", Items = new[] { 0, 1, 2 } };

            serializer.CallBase = true;
            serializer
                .Setup(s => s.CreateODataCollectionValue(enumerable, It.Is<IEdmTypeReference>(e => e.Definition == _edmIntType.Definition), writeContext))
                .Returns(collectionValue).Verifiable();

            // Act
            serializer.Object.WriteObject(enumerable, typeof(int[]), messageWriter, writeContext);

            // Assert
            serializer.Verify();
            stream.Seek(0, SeekOrigin.Begin);
            string result = new StreamReader(stream).ReadToEnd();
            Assert.Equal("{\"@odata.context\":\"http://any/$metadata#Collection(Edm.Int32)\",\"value\":[0,1,2]}", result);
        }