def irc_USER(self, prefix, params):
        """
        User message -- Set your realname.

        Parameters: <user> <mode> <unused> <realname>
        """
        # Note: who gives a crap about this?  The IUser has the real
        # information we care about.  Save it anyway, I guess, just
        # for fun.
        self.realname = params[-1]

        User message -- Set your realname.

        Parameters: <user> <mode> <unused> <realname>
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/words/service.py