Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.ServiceModel.Internals/System/Runtime/CallbackException.cs

@@ -0,0 +1,28 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//-----------------------------------------------------------------------------
+
+namespace System.Runtime
+{
+    using System;
+    using System.Runtime.Serialization;
+
+    [Serializable]
+    class CallbackException : FatalException
+    {
+        public CallbackException()
+        {
+        }
+
+        public CallbackException(string message, Exception innerException) : base(message, innerException)
+        {
+            // This can't throw something like ArgumentException because that would be worse than
+            // throwing the callback exception that was requested.
+            Fx.Assert(innerException != null, "CallbackException requires an inner exception.");
+            Fx.Assert(!Fx.IsFatal(innerException), "CallbackException can't be used to wrap fatal exceptions.");
+        }
+        protected CallbackException(SerializationInfo info, StreamingContext context) : base(info, context)
+        {
+        }
+    }
+}