Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/ISubscriptionToken.cs

@@ -0,0 +1,20 @@
+//------------------------------------------------------------------------------
+// <copyright file="ISubscriptionToken.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+namespace System.Web {
+
+    // Interface that is returned by event subscription methods and can be used to unsubscribe listeners.
+
+    public interface ISubscriptionToken {
+
+        // Returns a value stating whether the subscription is currently active
+        bool IsActive { get; }
+
+        // Unsubscribes from the event
+        void Unsubscribe();
+
+    }
+}