public override ODataEntry CreateEntry(SelectExpandNode selectExpandNode, EntityInstanceContext entityInstanceContext)
        {
            ODataEntry entry = base.CreateEntry(selectExpandNode, entityInstanceContext);

            Document document = entityInstanceContext.EntityInstance as Document;
            if (entry != null && document != null)
            {
                // annotate the document with the score.
                entry.InstanceAnnotations.Add(new ODataInstanceAnnotation("org.northwind.search.score", new ODataPrimitiveValue(document.Score)));
            }

            return entry;
        }

        [InlineData("ID", "Orders($select=ID),Orders($expand=Customer($select=ID))", true, "ID")] // deep expand and selects
        public void GetPropertiesToBeSelected_Selects_ExpectedProperties_OnCustomer(
            string select, string expand, bool specialCustomer, string structuralPropertiesToSelect)
        {
            // Arrange
            SelectExpandClause selectExpandClause =
                new ODataUriParser(_model.Model, serviceRoot: null).ParseSelectAndExpand(select, expand,  _model.Customer, _model.Customers);
            IEdmEntityType entityType = specialCustomer ? _model.SpecialCustomer : _model.Customer;

            // Act
            SelectExpandNode selectExpandNode = new SelectExpandNode(selectExpandClause, entityType, _model.Model);
            var result = selectExpandNode.SelectedStructuralProperties;

            // Assert
            Assert.Equal(structuralPropertiesToSelect, String.Join(",", result.Select(p => p.Name).OrderBy(n => n)));
        }

        [InlineData("ID", "Orders($select=ID),Orders($expand=Customer($select=ID))", true, "ID")] // deep expand and selects
        public void GetPropertiesToBeSelected_Selects_ExpectedProperties_OnCustomer(
            string select, string expand, bool specialCustomer, string structuralPropertiesToSelect)
        {
            // Arrange
            ODataQueryOptionParser parser = new ODataQueryOptionParser(_model.Model, _model.Customer, _model.Customers,
                new Dictionary<string, string> { { "$select", select }, { "$expand", expand } });

            SelectExpandClause selectExpandClause = parser.ParseSelectAndExpand();
            IEdmEntityType entityType = specialCustomer ? _model.SpecialCustomer : _model.Customer;

            // Act
            SelectExpandNode selectExpandNode = new SelectExpandNode(selectExpandClause, entityType, _model.Model);
            var result = selectExpandNode.SelectedStructuralProperties;

            // Assert
            Assert.Equal(structuralPropertiesToSelect, String.Join(",", result.Select(p => p.Name).OrderBy(n => n)));
        }

        public void CreateEntry_SetsEtagToNotNull_IfWithConcurrencyProperty()
        {
            // Arrange
            Mock<IEdmStructuralProperty> mockConcurrencyProperty = new Mock<IEdmStructuralProperty>();
            mockConcurrencyProperty.SetupGet(s => s.ConcurrencyMode).Returns(EdmConcurrencyMode.Fixed);
            mockConcurrencyProperty.SetupGet(s => s.Name).Returns("City");
            SelectExpandNode selectExpandNode = new SelectExpandNode
            {
                SelectedStructuralProperties = { new Mock<IEdmStructuralProperty>().Object, mockConcurrencyProperty.Object }
            };
            ODataProperty[] properties = new[] { new ODataProperty(), new ODataProperty() };
            Mock<ODataEntityTypeSerializer> serializer = new Mock<ODataEntityTypeSerializer>(_serializerProvider);
            serializer.CallBase = true;
            serializer
                .Setup(s => s.CreateStructuralProperty(selectExpandNode.SelectedStructuralProperties.ElementAt(0), _entityInstanceContext))
                .Returns(properties[0]);
            serializer
                .Setup(s => s.CreateStructuralProperty(selectExpandNode.SelectedStructuralProperties.ElementAt(1), _entityInstanceContext))
                .Returns(properties[1]);

            MockHttpRequestMessage request = new MockHttpRequestMessage();
            HttpConfiguration configuration = new HttpConfiguration();
            Mock<IETagHandler> mockETagHandler = new Mock<IETagHandler>();
            string tag = "\"'anycity'\"";
            EntityTagHeaderValue etagHeaderValue = new EntityTagHeaderValue(tag, isWeak: true);
            mockETagHandler.Setup(e => e.CreateETag(It.IsAny<IDictionary<string, object>>())).Returns(etagHeaderValue);
            configuration.SetETagHandler(mockETagHandler.Object);
            request.SetConfiguration(configuration);
            _entityInstanceContext.Request = request;

            // Act
            ODataEntry entry = serializer.Object.CreateEntry(selectExpandNode, _entityInstanceContext);

            // Assert
            Assert.Equal(etagHeaderValue.ToString(), entry.ETag);
        }

        public void CreateEntry_SetsETagToNull_IfModelDontHaveConcurrencyProperty()
        {
            // Arrange
            IEdmEntitySet orderSet = _model.EntityContainer.FindEntitySet("Orders");
            Order order = new Order()
            {
                Name = "Foo",
                Shipment = "Bar",
                ID = 10,
            };

            _writeContext.NavigationSource = orderSet;
            _entityInstanceContext = new EntityInstanceContext(_writeContext, orderSet.EntityType().AsReference(), order);

            SelectExpandNode selectExpandNode = new SelectExpandNode
            {
                SelectedStructuralProperties = { new Mock<IEdmStructuralProperty>().Object, new Mock<IEdmStructuralProperty>().Object }
            };
            ODataProperty[] properties = new[] { new ODataProperty(), new ODataProperty() };
            Mock<ODataEntityTypeSerializer> serializer = new Mock<ODataEntityTypeSerializer>(_serializerProvider);
            serializer.CallBase = true;

            serializer
                .Setup(s => s.CreateStructuralProperty(selectExpandNode.SelectedStructuralProperties.ElementAt(0), _entityInstanceContext))
                .Returns(properties[0]);
            serializer
                .Setup(s => s.CreateStructuralProperty(selectExpandNode.SelectedStructuralProperties.ElementAt(1), _entityInstanceContext))
                .Returns(properties[1]);

            MockHttpRequestMessage request = new MockHttpRequestMessage();
            request.SetConfiguration(new HttpConfiguration());
            _entityInstanceContext.Request = request;

            // Act
            ODataEntry entry = serializer.Object.CreateEntry(selectExpandNode, _entityInstanceContext);

            // Assert
            Assert.Null(entry.ETag);
        }

        public void CreateEntry_SetsETagToNull_IfRequestIsNull()
        {
            // Arrange
            SelectExpandNode selectExpandNode = new SelectExpandNode
            {
                SelectedStructuralProperties = { new Mock<IEdmStructuralProperty>().Object, new Mock<IEdmStructuralProperty>().Object }
            };
            ODataProperty[] properties = new[] { new ODataProperty(), new ODataProperty() };
            Mock<ODataEntityTypeSerializer> serializer = new Mock<ODataEntityTypeSerializer>(_serializerProvider);
            serializer.CallBase = true;

            serializer
                .Setup(s => s.CreateStructuralProperty(selectExpandNode.SelectedStructuralProperties.ElementAt(0), _entityInstanceContext))
                .Returns(properties[0]);
            serializer
                .Setup(s => s.CreateStructuralProperty(selectExpandNode.SelectedStructuralProperties.ElementAt(1), _entityInstanceContext))
                .Returns(properties[1]);

            // Act
            ODataEntry entry = serializer.Object.CreateEntry(selectExpandNode, _entityInstanceContext);

            // Assert
            Assert.Null(entry.ETag);
        }

        public void CreateEntry_Calls_CreateStructuralProperty_ForEachSelectedStructuralProperty()
        {
            // Arrange
            SelectExpandNode selectExpandNode = new SelectExpandNode
            {
                SelectedStructuralProperties = { new Mock<IEdmStructuralProperty>().Object, new Mock<IEdmStructuralProperty>().Object }
            };
            ODataProperty[] properties = new ODataProperty[] { new ODataProperty(), new ODataProperty() };
            Mock<ODataEntityTypeSerializer> serializer = new Mock<ODataEntityTypeSerializer>(_serializerProvider);
            serializer.CallBase = true;

            serializer
                .Setup(s => s.CreateStructuralProperty(selectExpandNode.SelectedStructuralProperties.ElementAt(0), _entityInstanceContext))
                .Returns(properties[0])
                .Verifiable();
            serializer
                .Setup(s => s.CreateStructuralProperty(selectExpandNode.SelectedStructuralProperties.ElementAt(1), _entityInstanceContext))
                .Returns(properties[1])
                .Verifiable();

            // Act
            ODataEntry entry = serializer.Object.CreateEntry(selectExpandNode, _entityInstanceContext);

            // Assert
            serializer.Verify();
            Assert.Equal(properties, entry.Properties);
        }

            public override ODataEntry CreateEntry(SelectExpandNode selectExpandNode, EntityInstanceContext entityInstanceContext)
            {
                ODataEntry entry = base.CreateEntry(selectExpandNode, entityInstanceContext);

                // instance annotation on entry
                ODataPrimitiveValue guidValue = new ODataPrimitiveValue(new Guid("A6E07EAC-AD49-4BF7-A06E-203FF4D4B0D8"));
                entry.InstanceAnnotations.Add(new ODataInstanceAnnotation("Entry.GuidAnnotation", guidValue));

                ODataPrimitiveValue strValue = new ODataPrimitiveValue("Hello World.");
                entry.InstanceAnnotations.Add(new ODataInstanceAnnotation("Hello.World", strValue));
                return entry;
            }

        [InlineData(null, "NS.SpecialCustomer/SpecialOrders", true, "SpecialOrders")] // expand derived navigation property on derived type -> expand requested
        public void GetNavigationPropertiesToBeExpanded_Expands_ExpectedProperties(
            string select, string expand, bool specialCustomer, string navigationPropertiesToExpand)
        {
            // Arrange
            SelectExpandClause selectExpandClause =
                new ODataUriParser(_model.Model, serviceRoot: null).ParseSelectAndExpand(select, expand, _model.Customer, _model.Customers);

            IEdmEntityType entityType = specialCustomer ? _model.SpecialCustomer : _model.Customer;

            // Act
            SelectExpandNode selectExpandNode = new SelectExpandNode(selectExpandClause, entityType, _model.Model);
            var result = selectExpandNode.ExpandedNavigationProperties.Keys;

            // Assert
            Assert.Equal(navigationPropertiesToExpand, String.Join(",", result.Select(p => p.Name).OrderBy(n => n)));
        }

        public void CreateEntry_UsesCorrectTypeName()
        {
            EntityInstanceContext instanceContext =
                new EntityInstanceContext { EntityType = _customerType.EntityDefinition(), SerializerContext = _writeContext };
            Mock<ODataEntityTypeSerializer> serializer = new Mock<ODataEntityTypeSerializer>(_serializerProvider);
            serializer.CallBase = true;
            SelectExpandNode selectExpandNode = new SelectExpandNode();

            // Act
            ODataEntry entry = serializer.Object.CreateEntry(selectExpandNode, instanceContext);

            // Assert
            Assert.Equal("Default.Customer", entry.TypeName);
        }

        public void WriteObjectInline_ExpandsUsingInnerSerializerUsingRightContext_ExpandedNavigationProperties()
        {
            // Arrange
            IEdmEntityType customerType = _customerSet.EntityType();
            IEdmNavigationProperty ordersProperty = customerType.NavigationProperties().Single(p => p.Name == "Orders");

            ODataQueryOptionParser parser = new ODataQueryOptionParser(_model, customerType, _customerSet,
                new Dictionary<string, string> { { "$select", "Orders" }, { "$expand", "Orders" } });
            SelectExpandClause selectExpandClause = parser.ParseSelectAndExpand();

            SelectExpandNode selectExpandNode = new SelectExpandNode
            {
                ExpandedNavigationProperties = 
                { 
                    { ordersProperty, selectExpandClause.SelectedItems.OfType<ExpandedNavigationSelectItem>().Single().SelectAndExpand }
                }
            };
            Mock<ODataWriter> writer = new Mock<ODataWriter>();

            Mock<ODataEdmTypeSerializer> innerSerializer = new Mock<ODataEdmTypeSerializer>(ODataPayloadKind.Entry);
            innerSerializer
                .Setup(s => s.WriteObjectInline(_customer.Orders, ordersProperty.Type, writer.Object, It.IsAny<ODataSerializerContext>()))
                .Callback((object o, IEdmTypeReference t, ODataWriter w, ODataSerializerContext context) =>
                    {
                        Assert.Same(context.NavigationSource.Name, "Orders");
                        Assert.Same(context.SelectExpandClause, selectExpandNode.ExpandedNavigationProperties.Single().Value);
                    })
                .Verifiable();

            Mock<ODataSerializerProvider> serializerProvider = new Mock<ODataSerializerProvider>();
            serializerProvider.Setup(p => p.GetEdmTypeSerializer(ordersProperty.Type))
                .Returns(innerSerializer.Object);
            Mock<ODataEntityTypeSerializer> serializer = new Mock<ODataEntityTypeSerializer>(serializerProvider.Object);
            serializer.Setup(s => s.CreateSelectExpandNode(It.IsAny<EntityInstanceContext>())).Returns(selectExpandNode);
            serializer.CallBase = true;
            _writeContext.SelectExpandClause = selectExpandClause;

            // Act
            serializer.Object.WriteObjectInline(_customer, _customerType, writer.Object, _writeContext);

            // Assert
            innerSerializer.Verify();
            // check that the context is rolled back
            Assert.Same(_writeContext.NavigationSource.Name, "Customers");
            Assert.Same(_writeContext.SelectExpandClause, selectExpandClause);
        }

        public void WriteObjectInline_Calls_CreateNavigationLink_ForEachExpandedNavigationProperty()
        {
            // Arrange
            SelectExpandNode selectExpandNode = new SelectExpandNode
            {
                ExpandedNavigationProperties =
                {
                    { new Mock<IEdmNavigationProperty>().Object, null },
                    { new Mock<IEdmNavigationProperty>().Object, null }
                }
            };
            Mock<ODataWriter> writer = new Mock<ODataWriter>();
            Mock<ODataEntityTypeSerializer> serializer = new Mock<ODataEntityTypeSerializer>(_serializerProvider);
            serializer.Setup(s => s.CreateSelectExpandNode(It.IsAny<EntityInstanceContext>())).Returns(selectExpandNode);
            var expandedNavigationProperties = selectExpandNode.ExpandedNavigationProperties.ToList();

            serializer.Setup(s => s.CreateNavigationLink(expandedNavigationProperties[0].Key, It.IsAny<EntityInstanceContext>())).Verifiable();
            serializer.Setup(s => s.CreateNavigationLink(expandedNavigationProperties[1].Key, It.IsAny<EntityInstanceContext>())).Verifiable();
            serializer.CallBase = true;

            // Act
            serializer.Object.WriteObjectInline(_customer, _customerType, writer.Object, _writeContext);

            // Assert
            serializer.Verify();
        }

        public void WriteObjectInline_WritesNavigationLinksReturnedBy_CreateNavigationLink_ForEachSelectedNavigationProperty()
        {
            // Arrange
            SelectExpandNode selectExpandNode = new SelectExpandNode
            {
                SelectedNavigationProperties =
                {
                    new Mock<IEdmNavigationProperty>().Object,
                    new Mock<IEdmNavigationProperty>().Object
                }
            };
            ODataNavigationLink[] navigationLinks = new[]
            {
                new ODataNavigationLink(),
                new ODataNavigationLink()
            };
            Mock<ODataEntityTypeSerializer> serializer = new Mock<ODataEntityTypeSerializer>(_serializerProvider);
            serializer.Setup(s => s.CreateSelectExpandNode(It.IsAny<EntityInstanceContext>())).Returns(selectExpandNode);
            serializer
                .Setup(s => s.CreateNavigationLink(selectExpandNode.SelectedNavigationProperties.ElementAt(0), It.IsAny<EntityInstanceContext>()))
                .Returns(navigationLinks[0]);
            serializer
                .Setup(s => s.CreateNavigationLink(selectExpandNode.SelectedNavigationProperties.ElementAt(1), It.IsAny<EntityInstanceContext>()))
                .Returns(navigationLinks[1]);
            serializer.CallBase = true;

            Mock<ODataWriter> writer = new Mock<ODataWriter>();
            writer.Setup(w => w.WriteStart(navigationLinks[0])).Verifiable();
            writer.Setup(w => w.WriteStart(navigationLinks[1])).Verifiable();

            // Act
            serializer.Object.WriteObjectInline(_customer, _customerType, writer.Object, _writeContext);

            // Assert
            writer.Verify();
        }

        public void WriteObjectInline_Calls_CreateEntry()
        {
            // Arrange
            SelectExpandNode selectExpandNode = new SelectExpandNode();
            Mock<ODataEntityTypeSerializer> serializer = new Mock<ODataEntityTypeSerializer>(_serializerProvider);
            ODataWriter writer = new Mock<ODataWriter>().Object;

            serializer.Setup(s => s.CreateSelectExpandNode(It.IsAny<EntityInstanceContext>())).Returns(selectExpandNode);
            serializer.Setup(s => s.CreateEntry(selectExpandNode, It.Is<EntityInstanceContext>(e => Verify(e, _customer, _writeContext)))).Verifiable();
            serializer.CallBase = true;

            // Act
            serializer.Object.WriteObjectInline(_customer, _customerType, writer, _writeContext);

            // Assert
            serializer.Verify();
        }

        public void WriteObjectInline_SetsParentContext_ForExpandedNavigationProperties()
        {
            // Arrange
            ODataWriter mockWriter = new Mock<ODataWriter>().Object;
            IEdmNavigationProperty ordersProperty = _customerSet.EntityType().DeclaredNavigationProperties().Single();
            Mock<ODataEdmTypeSerializer> expandedItemSerializer = new Mock<ODataEdmTypeSerializer>(ODataPayloadKind.Feed);
            Mock<ODataSerializerProvider> serializerProvider = new Mock<ODataSerializerProvider>();
            serializerProvider.Setup(p => p.GetEdmTypeSerializer(ordersProperty.Type))
                .Returns(expandedItemSerializer.Object);

            SelectExpandNode selectExpandNode = new SelectExpandNode
            {
                ExpandedNavigationProperties = 
                {
                     { ordersProperty, new SelectExpandClause(new SelectItem[0], allSelected: true) }
                }
            };
            Mock<ODataEntityTypeSerializer> serializer = new Mock<ODataEntityTypeSerializer>(serializerProvider.Object);
            serializer.Setup(s => s.CreateSelectExpandNode(It.IsAny<EntityInstanceContext>())).Returns(selectExpandNode);
            serializer.Setup(s => s.CreateEntry(selectExpandNode, _entityInstanceContext)).Returns(new ODataEntry());
            serializer.CallBase = true;

            // Act
            serializer.Object.WriteObjectInline(_customer, _customerType, mockWriter, _writeContext);

            // Assert
            expandedItemSerializer.Verify(
                s => s.WriteObjectInline(It.IsAny<object>(), ordersProperty.Type, mockWriter,
                    It.Is<ODataSerializerContext>(c => c.ExpandedEntity.SerializerContext == _writeContext)));
        }

        /// <summary>
        /// Creates the <see cref="ODataEntry"/> to be written while writing this entity.
        /// </summary>
        /// <param name="selectExpandNode">The <see cref="SelectExpandNode"/> describing the response graph.</param>
        /// <param name="entityInstanceContext">The context for the entity instance being written.</param>
        /// <returns>The created <see cref="ODataEntry"/>.</returns>
        public virtual ODataEntry CreateEntry(SelectExpandNode selectExpandNode, EntityInstanceContext entityInstanceContext)
        {
            if (selectExpandNode == null)
            {
                throw Error.ArgumentNull("selectExpandNode");
            }
            if (entityInstanceContext == null)
            {
                throw Error.ArgumentNull("entityInstanceContext");
            }

            string typeName = entityInstanceContext.EntityType.FullName();

            ODataEntry entry = new ODataEntry
            {
                TypeName = typeName,
                Properties = CreateStructuralPropertyBag(selectExpandNode.SelectedStructuralProperties, entityInstanceContext),
                Actions = CreateODataActions(selectExpandNode.SelectedActions, entityInstanceContext)
            };

            IEdmEntityType pathType = GetODataPathType(entityInstanceContext.SerializerContext);
            AddTypeNameAnnotationAsNeeded(entry, pathType, entityInstanceContext.SerializerContext.MetadataLevel);

            if (entityInstanceContext.EntitySet != null)
            {
                IEdmModel model = entityInstanceContext.SerializerContext.Model;
                EntitySetLinkBuilderAnnotation linkBuilder = model.GetEntitySetLinkBuilder(entityInstanceContext.EntitySet);
                EntitySelfLinks selfLinks = linkBuilder.BuildEntitySelfLinks(entityInstanceContext, entityInstanceContext.SerializerContext.MetadataLevel);

                if (selfLinks.IdLink != null)
                {
                    entry.Id = new Uri(selfLinks.IdLink);
                }

                if (selfLinks.ReadLink != null)
                {
                    entry.ReadLink = selfLinks.ReadLink;
                }

                if (selfLinks.EditLink != null)
                {
                    entry.EditLink = selfLinks.EditLink;
                }

                string etag = CreateETag(entityInstanceContext);
                if (etag != null)
                {
                    entry.ETag = etag;
                }
            }

            return entry;
        }

        public void CreateEntry_IgnoresProperty_IfCreateStructuralPropertyReturnsNull()
        {
            // Arrange
            SelectExpandNode selectExpandNode = new SelectExpandNode
            {
                SelectedStructuralProperties = { new Mock<IEdmStructuralProperty>().Object }
            };
            Mock<ODataEntityTypeSerializer> serializer = new Mock<ODataEntityTypeSerializer>(_serializerProvider);
            serializer.CallBase = true;

            serializer
                .Setup(s => s.CreateStructuralProperty(selectExpandNode.SelectedStructuralProperties.ElementAt(0), _entityInstanceContext))
                .Returns<ODataProperty>(null);

            // Act
            ODataEntry entry = serializer.Object.CreateEntry(selectExpandNode, _entityInstanceContext);

            // Assert
            serializer.Verify();
            Assert.Empty(entry.Properties);
        }

        public void WriteObjectInline_CanExpandNavigationProperty_ContainingEdmObject()
        {
            // Arrange
            IEdmEntityType customerType = _customerSet.EntityType();
            IEdmNavigationProperty ordersProperty = customerType.NavigationProperties().Single(p => p.Name == "Orders");

            Mock<IEdmObject> orders = new Mock<IEdmObject>();
            orders.Setup(o => o.GetEdmType()).Returns(ordersProperty.Type);
            object ordersValue = orders.Object;

            Mock<IEdmEntityObject> customer = new Mock<IEdmEntityObject>();
            customer.Setup(c => c.TryGetPropertyValue("Orders", out ordersValue)).Returns(true);
            customer.Setup(c => c.GetEdmType()).Returns(customerType.AsReference());

            ODataQueryOptionParser parser = new ODataQueryOptionParser(_model, customerType, _customerSet,
                new Dictionary<string, string> { { "$select", "Orders" }, { "$expand", "Orders" } });
            SelectExpandClause selectExpandClause = parser.ParseSelectAndExpand();

            SelectExpandNode selectExpandNode = new SelectExpandNode();
            selectExpandNode.ExpandedNavigationProperties[ordersProperty] = selectExpandClause.SelectedItems.OfType<ExpandedNavigationSelectItem>().Single().SelectAndExpand;

            Mock<ODataWriter> writer = new Mock<ODataWriter>();

            Mock<ODataEdmTypeSerializer> ordersSerializer = new Mock<ODataEdmTypeSerializer>(ODataPayloadKind.Entry);
            ordersSerializer.Setup(s => s.WriteObjectInline(ordersValue, ordersProperty.Type, writer.Object, It.IsAny<ODataSerializerContext>())).Verifiable();

            Mock<ODataSerializerProvider> serializerProvider = new Mock<ODataSerializerProvider>();
            serializerProvider.Setup(p => p.GetEdmTypeSerializer(ordersProperty.Type)).Returns(ordersSerializer.Object);

            Mock<ODataEntityTypeSerializer> serializer = new Mock<ODataEntityTypeSerializer>(serializerProvider.Object);
            serializer.Setup(s => s.CreateSelectExpandNode(It.IsAny<EntityInstanceContext>())).Returns(selectExpandNode);
            serializer.CallBase = true;

            // Act
            serializer.Object.WriteObjectInline(customer.Object, _customerType, writer.Object, _writeContext);

            //Assert
            ordersSerializer.Verify();
        }

        public void CreateEntry_Calls_CreateODataAction_ForEachSelectAction()
        {
            // Arrange
            ODataAction[] actions = new ODataAction[] { new ODataAction(), new ODataAction() };
            SelectExpandNode selectExpandNode = new SelectExpandNode
            {
                SelectedActions = { new Mock<IEdmAction>().Object, new Mock<IEdmAction>().Object }
            };
            Mock<ODataEntityTypeSerializer> serializer = new Mock<ODataEntityTypeSerializer>(_serializerProvider);
            serializer.CallBase = true;

            serializer.Setup(s => s.CreateODataAction(selectExpandNode.SelectedActions.ElementAt(0), _entityInstanceContext)).Returns(actions[0]).Verifiable();
            serializer.Setup(s => s.CreateODataAction(selectExpandNode.SelectedActions.ElementAt(1), _entityInstanceContext)).Returns(actions[1]).Verifiable();

            // Act
            ODataEntry entry = serializer.Object.CreateEntry(selectExpandNode, _entityInstanceContext);

            // Assert
            Assert.Equal(actions, entry.Actions);
            serializer.Verify();
        }

        /// <summary>
        /// Creates the <see cref="SelectExpandNode"/> that describes the set of properties and actions to select and expand while writing this entity.
        /// </summary>
        /// <param name="entityInstanceContext">Contains the entity instance being written and the context.</param>
        /// <returns>
        /// The <see cref="SelectExpandNode"/> that describes the set of properties and actions to select and expand while writing this entity.
        /// </returns>
        public virtual SelectExpandNode CreateSelectExpandNode(EntityInstanceContext entityInstanceContext)
        {
            if (entityInstanceContext == null)
            {
                throw Error.ArgumentNull("entityInstanceContext");
            }

            ODataSerializerContext writeContext = entityInstanceContext.SerializerContext;
            IEdmEntityType entityType = entityInstanceContext.EntityType;

            object selectExpandNode;
            Tuple<SelectExpandClause, IEdmEntityType> key = Tuple.Create(writeContext.SelectExpandClause, entityType);
            if (!writeContext.Items.TryGetValue(key, out selectExpandNode))
            {
                // cache the selectExpandNode so that if we are writing a feed we don't have to construct it again.
                selectExpandNode = new SelectExpandNode(entityType, writeContext);
                writeContext.Items[key] = selectExpandNode;
            }
            return selectExpandNode as SelectExpandNode;
        }