Sends a message from the framework to one of its executors.

        These messages are best effort; do not expect a framework message to be
        retransmitted in any reliable fashion.

def message(self, executor_id, slave_id, message):
        """Sends a message from the framework to one of its executors.

        These messages are best effort; do not expect a framework message to be
        retransmitted in any reliable fashion.
        """
        logging.info('Sends message `{}` to executor `{}` on slave `{}`'.format(
                     message, executor_id, slave_id))
        return self.driver.sendFrameworkMessage(encode(executor_id),
                                                encode(slave_id),
                                                message)