public override void Push(IMessage message, IMessageClient messageClient)
 {
     _lock.AcquireReaderLock();
     try
     {
         if (IsClosed || IsClosing || IsDisconnecting)
         {
             return; // Already shutting down.
         }
     }
     finally
     {
         _lock.ReleaseReaderLock();
     }
     RtmpHandler.Push(this, message, messageClient);
 }