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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def all_active(cls):
 """ List active queues, based on their lengths in Redis. Warning, uses the unscalable KEYS redis command """


        prefix = context.get_current_config()["redis_prefix"]
        queues = []
        for key in context.connections.redis.keys():
            if key.startswith(prefix):
                queues.append(Queue(key[len(prefix) + 3:]))

        return queues