def flash(self, msg, queue='', allow_duplicate=True):
        storage = self.setdefault('_f_' + queue, [])
        if allow_duplicate or (storage not in msg):
            storage.append(msg)
            self.changed()  # notify redis of change to ``storage`` mutable
dataset/ETHPy150Open ericrasmussen/pyramid_redis_sessions/pyramid_redis_sessions/session.py/RedisSession.flash/swapped operands of `not in`