def stats(self, arg=None):
        """
        Get some stats from the server. It will be available as a dict.

        @param arg: An optional additional string which will be sent along
            with the I{stats} command.  The interpretation of this value by
            the server is left undefined by the memcache protocol
            specification.
        @type arg: L{None} or L{bytes}

        @return: a deferred that will fire with a L{dict} of the available
            statistics.
        @rtype: L{Deferred}
        """
        if arg:
            cmd = b"stats " + arg
        else:
            cmd = b"stats"
        if self._disconnected:
            return fail(RuntimeError("not connected"))
        self.sendLine(cmd)
        cmdObj = Command(b"stats", values={})
        self._current.append(cmdObj)
        return cmdObj._deferred

        Get some stats from the server. It will be available as a dict.

        @param arg: An optional additional string which will be sent along
            with the I{stats} command.  The interpretation of this value by
            the server is left undefined by the memcache protocol
            specification.
        @type arg: L{None} or L{bytes}

        @return: a deferred that will fire with a L{dict} of the available
            statistics.
        @rtype: L{Deferred}
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/protocols/memcache.py