Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.IdentityModel/System/IdentityModel/WSMetadataExchangeConstants.cs

@@ -0,0 +1,18 @@
+//-----------------------------------------------------------------------
+// <copyright file="WSMetadataExchangeConstants.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace System.IdentityModel.Protocols
+{
+    /// <summary>
+    /// The <c>WSMetadataExchangeConstants</c> class contains constants used in the WS-Mex protocol.
+    /// </summary>
+    internal static class WSMetadataExchangeConstants
+    {
+#pragma warning disable 1591
+        public const string Namespace = "http://schemas.xmlsoap.org/ws/2004/09/mex";
+#pragma warning restore 1591
+    }
+}