Moving CreateEnumerable tests.

Ix.NET/Source/System.Interactive.Async.Tests/AsyncTests.Creation.cs

@@ -11,10 +11,5 @@ namespace Tests
 {
     public partial class AsyncTests
     {
-        [Fact]
-        public void Create_Null()
-        {
-            AssertThrows<ArgumentNullException>(() => AsyncEnumerable.CreateEnumerable<int>(default(Func<IAsyncEnumerator<int>>)));
-        }
     }
 }

Ix.NET/Source/System.Linq.Async.Tests/System/Linq/Operators/CreateEnumerable.cs

@@ -0,0 +1,20 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information. 
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Xunit;
+
+namespace Tests
+{
+    public class CreateEnumerable : AsyncEnumerableTests
+    {
+        [Fact]
+        public void CreateEnumerable_Null()
+        {
+            AssertThrows<ArgumentNullException>(() => AsyncEnumerable.CreateEnumerable<int>(default(Func<IAsyncEnumerator<int>>)));
+        }
+    }
+}