<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def send_cmds(self, *cmds):
 """ Tags and sends the commands to the Switchboard server, returning None. Each cmd be a 2-tuple where the first element is the method name, """

        promise = aplus.Promise()
        tagged_cmds = list(self._tag_cmds(*cmds))
        logger.debug("Sending cmds: %s", tagged_cmds)

        cmd_group = _get_cmds_id(*tagged_cmds)
        self._cmd_groups[cmd_group] = (tagged_cmds, promise)
        self.send(json.dumps(tagged_cmds))
        return promise