async def on_raw_401(self, message):
        """ No such nick/channel. """
        nickname = message.params[1]

        # Remove nickname from whois requests if it involves one of ours.
        if nickname in self._pending['whois']:
            future = self._pending['whois'].pop(nickname)
            future.set_result(None)
            del self._whois_info[nickname]
No such nick/channel.