Add SetContentFromEnumCollection method to RequestInformation class

src/abstractions/RequestInformation.cs

@@ -513,5 +513,37 @@ public void SetContentFromEnum<T>(IRequestAdapter requestAdapter, string content
             Headers.TryAdd(ContentTypeHeader, contentType);
             Content = writer.GetSerializedContent();
         }
+
+        /// <summary>
+        /// Sets the request body from a collection of enum values with the specified content type.
+        /// </summary>
+        /// <param name="requestAdapter">The core service to get the serialization writer from.</param>
+        /// <param name="items">The enum values to serialize.</param>
+        /// <param name="contentType">The content type to set.</param>
+        /// <typeparam name="T">The enum type to serialize.</typeparam>
+#if NET5_0_OR_GREATER
+        public void SetContentFromEnumCollection<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicFields)] T>(IRequestAdapter requestAdapter, string contentType, IEnumerable<T?> items) where T : struct, Enum
+#else
+        public void SetContentFromEnumCollection<T>(IRequestAdapter requestAdapter, string contentType, IEnumerable<T?> items) where T : struct, Enum
+#endif
+        {
+            using var activity = _activitySource?.StartActivity(nameof(SetContentFromEnumCollection));
+            using var writer = GetSerializationWriter(requestAdapter, contentType, items);
+
+            T? firstNonNullItem = null;
+            foreach(var item in items)
+            {
+                if(item != null)
+                {
+                    firstNonNullItem = item;
+                    break;
+                }
+            }
+
+            SetRequestType(firstNonNullItem, activity);
+            writer.WriteCollectionOfEnumValues(null, items);
+            Headers.TryAdd(ContentTypeHeader, contentType);
+            Content = writer.GetSerializedContent();
+        }
     }
 }

tests/abstractions/RequestInformationTests.cs

@@ -497,6 +497,26 @@ public void SetsEnumContent()
             serializationWriterMock.Verify(x => x.WriteCollectionOfEnumValues(It.IsAny<string>(), It.IsAny<IEnumerable<TestEnum?>>()), Times.Never);
         }
         [Fact]
+        public void SetsEnumCollectionContent()
+        {
+            var requestAdapterMock = new Mock<IRequestAdapter>();
+            var serializationWriterMock = new Mock<ISerializationWriter>();
+            var serializationWriterFactoryMock = new Mock<ISerializationWriterFactory>();
+            serializationWriterFactoryMock.Setup(x => x.GetSerializationWriter(It.IsAny<string>())).Returns(serializationWriterMock.Object);
+            requestAdapterMock.SetupGet(x => x.SerializationWriterFactory).Returns(serializationWriterFactoryMock.Object);
+            var requestInfo = new RequestInformation
+            {
+                HttpMethod = Method.POST,
+                UrlTemplate = "{+baseurl}/users{?%24count}"
+            };
+
+            requestInfo.SetContentFromEnumCollection<TestEnum>(requestAdapterMock.Object, "application/json", new TestEnum?[] { TestEnum.First, TestEnum.Second });
+
+            // Assert we now have an option
+            serializationWriterMock.Verify(x => x.WriteEnumValue<TestEnum>(It.IsAny<string>(), It.IsAny<TestEnum>()), Times.Never);
+            serializationWriterMock.Verify(x => x.WriteCollectionOfEnumValues(It.IsAny<string>(), It.IsAny<IEnumerable<TestEnum?>>()), Times.Once);
+        }
+        [Fact]
         public void SetsScalarCollectionContent()
         {
             var requestAdapterMock = new Mock<IRequestAdapter>();