code: public void unsubscribeW( String name, Map header ) throws InterruptedException {
      String receipt = addReceipt( header );
      unsubscribe( name, (HashMap)null );
      waitOnReceipt( receipt );
    }
docs: Unsubscribe from a channel.  Automatically unregisters all
  listeners of the channel.  To re-subscribe with listeners,
  subscribe must be passed the listeners again.  This method
  blocks until a receipt is received from the server.
  
  @param name The name of the channel to unsubscribe from.