Moving Expand to AsyncEnumerableEx.

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

@@ -3138,8 +3138,8 @@ namespace Tests
         [Fact]
         public void Expand_Null()
         {
-            AssertThrows<ArgumentNullException>(() => AsyncEnumerable.Expand(default(IAsyncEnumerable<int>), x => default(IAsyncEnumerable<int>)));
-            AssertThrows<ArgumentNullException>(() => AsyncEnumerable.Expand(AsyncEnumerable.Return(42), default(Func<int, IAsyncEnumerable<int>>)));
+            AssertThrows<ArgumentNullException>(() => AsyncEnumerableEx.Expand(default(IAsyncEnumerable<int>), x => default(IAsyncEnumerable<int>)));
+            AssertThrows<ArgumentNullException>(() => AsyncEnumerableEx.Expand(AsyncEnumerable.Return(42), default(Func<int, IAsyncEnumerable<int>>)));
         }
 
         [Fact]

Ix.NET/Source/System.Interactive.Async/Expand.cs → Ix.NET/Source/System.Interactive.Async/System/Linq/Operators/Expand.cs

@@ -8,7 +8,7 @@ using System.Threading.Tasks;
 
 namespace System.Linq
 {
-    public static partial class AsyncEnumerable
+    public static partial class AsyncEnumerableEx
     {
         public static IAsyncEnumerable<TSource> Expand<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, IAsyncEnumerable<TSource>> selector)
         {