public static Guid SetTimeout (int delay, Action action)
 {
    Guid g = Guid.NewGuid ();
    Thread t = new Thread (() =>
     {
         Thread.Sleep (delay);
         _setTimeoutHandles.Remove (g);
         action ();
     });
     _setTimeoutHandles.Add (g, t);
     t.Start ();
   return g;
 }