code: public void subscribeW( String name, Listener listener, Map header ) 
    throws InterruptedException {
      String receipt = addReceipt( header );
      subscribe( name, listener, header );
      waitOnReceipt( receipt );
    }
docs: Subscribe to a channel.  This method blocks until it receives a
  receipt from the server.
  
  @param name The name of the channel to listen on
  @param header Additional headers to send to the server.
  @param listener A listener to receive messages sent to the channel