def _get_broadcast_cursor(self, queue):
        try:
            return self._broadcast_cursors[queue]
        except __HOLE__:
            # Cursor may be absent when Channel created more than once.
            # _fanout_queues is a class-level mutable attribute so it's
            # shared over all Channel instances.
            return self._create_broadcast_cursor(
                self._fanout_queues[queue], None, None, queue,
            )
dataset/ETHPy150Open celery/kombu/kombu/transport/mongodb.py/Channel._get_broadcast_cursor