def reset_generation(self, member_id=UNKNOWN_MEMBER_ID):
        """Reset the generation and member_id because we have fallen out of the group."""
        with self._lock:
            self._generation = Generation(DEFAULT_GENERATION_ID, member_id, None)
            self.rejoin_needed = True
            self.state = MemberState.UNJOINED
Reset the generation and member_id because we have fallen out of the group.
kafka/coordinator/base.py