code: public void commitW( Map header ) throws InterruptedException { 
      String receipt = addReceipt( header );
      transmit( Command.COMMIT, header ); 
      waitOnReceipt( receipt );
    }
docs: Commits a transaction, causing any messages sent since begin()
  was called to be delivered.  This method does not return until
  the server has confirmed that the commit was successfull.