code: public void addMessageListener(MessageListener<? extends Message> messageListener) {
          addListener(messageListener.getChannelIdentifier(), messageListener.getMessageType(), messageListener);
      }
docs: Add a messageListener to the Firmta object which will fire whenever a matching message is received
  over the SerialPort. If the listener is for a ChannelMessage, the listener will fire regardless of which
  channel (pin) the message is coming from.
  
  @param messageListener MessageListener object to handle a received Message event over the SerialPort.