'Initialization method for the Cola message queue.
:param working_dir: data for the mq should be serialized into this dir
:param rpc_server: can be null when running under local mode
:param addr: this worker address, as the ``ip:port``
:param addrs: the whole worker addresses of the cluster
:param app_name: ``optional`` if the mq used for some app
:param copies: default as 1, an object will be delivered to the node
on the hash ring if copy is 1
:param n_priorities: the mq will include multiple priorities
:param deduper: ``optional`` :class:`~cola.core.dedup.Deduper` instance
for removing the duplication'

def __init__(self, working_dir, rpc_server, addr, addrs, app_name=None, copies=1, n_priorities=3, deduper=None):

    super(MessageQueue, self).__init__(working_dir, rpc_server, addr, addrs, copies=copies, n_priorities=n_priorities, deduper=deduper, app_name=app_name)
    self.stopped = multiprocessing.Event()
    self.agents = []
    self.threads = []
    self.clients = {}
