'Constructor for RedisQueue
maxsize:    an integer that sets the upperbound limit on the number of
items that can be placed in the queue.
lazy_limit: redis queue is shared via instance, a lazy size limit is used
for better performance.'

def __init__(self, name, host='localhost', port=6379, db=0, maxsize=0, lazy_limit=True, password=None, cluster_nodes=None):

    self.name = name
    if (cluster_nodes is not None):
        from rediscluster import StrictRedisCluster
        self.redis = StrictRedisCluster(startup_nodes=cluster_nodes)
    else:
        self.redis = redis.StrictRedis(host=host, port=port, db=db, password=password)
    self.maxsize = maxsize
    self.lazy_limit = lazy_limit
    self.last_qsize = 0
