def send_msg(self, msg, wait_nak=True, wait_timeout=WAIT_TIMEOUT):
        """Place a message on the send queue for sending.

        Message are sent in the order they are placed in the queue.
        """
        msg_info = MessageInfo(msg=msg, wait_nak=wait_nak,
                               wait_timeout=wait_timeout)
        _LOGGER.debug("Queueing msg: %s", msg)
        self._send_queue.put_nowait(msg_info)
Place a message on the send queue for sending.

        Message are sent in the order they are placed in the queue.