private static void DestroyOnReadyStateChangeSignalSender(OnReadyStateChangeSignalSender sender)
 {
     lock (_onReadyStateChangeSignalHandlers)
     {
         _onReadyStateChangeSignalHandlers.Remove(sender.SignalId);
     }
 }
 private static OnReadyStateChangeSignalSender CreateOnReadyStateChangeSignalSender(OnReadyStateChangeSignalHandler handler)
 {
     OnReadyStateChangeSignalSender signalSender;
     lock (_onReadyStateChangeSignalHandlers)
     {
         int signalId = ++_customSignalIdCounter;
         _onReadyStateChangeSignalHandlers[signalId] = handler;
         signalSender = new OnReadyStateChangeSignalSender
         {
             SignalId = signalId
         };
     }
     return signalSender;
 }