def publish(self, message, tag=b''):
        """
        Publish `message` with specified `tag`.

        :param message: message data
        :type message: str
        :param tag: message tag
        :type tag: str
        """
        self.send(tag + b'\0' + message)
Publish `message` with specified `tag`.

        :param message: message data
        :type message: str
        :param tag: message tag
        :type tag: str