Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

external/aspnetwebstack/src/System.Web.Mvc/UrlParameter.cs

@@ -0,0 +1,22 @@
+// Copyright (c) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
+
+using System.Diagnostics.CodeAnalysis;
+
+namespace System.Web.Mvc
+{
+    public sealed class UrlParameter
+    {
+        [SuppressMessage("Microsoft.Security", "CA2104:DoNotDeclareReadOnlyMutableReferenceTypes", Justification = "This type is immutable.")]
+        public static readonly UrlParameter Optional = new UrlParameter();
+
+        // singleton constructor
+        private UrlParameter()
+        {
+        }
+
+        public override string ToString()
+        {
+            return String.Empty;
+        }
+    }
+}