code: @Override
      public void setMessageListener(MessageListener listener) throws JMSException {
          // pass control to the internal method
          boolean checkManaged = true;
          _setMessageListener(listener, checkManaged);
      }
docs: assign a MessageListener to this consumer for async message delivery.
  
  @param listener an instance of MessageListener supplied by an application for
  the purpose of consuming messages. If null, remove any previously assigned
  MessageListener.
  @see javax.jms.MessageConsumer#setMessageListener(MessageListener)