def __init__(self, mapreduce_spec, shard_state):
    # TODO(user): Make these properties protected
    self.mapreduce_spec = mapreduce_spec
    self.shard_state = shard_state

    # TODO(user): These properties can stay public.
    self.mutation_pool = MutationPool()
    self.counters = Counters(shard_state)

    self._pools = {}
    self.register_pool("mutation_pool", self.mutation_pool)
    self.register_pool("counters", self.counters)
Constructor.
dataset/ETHPy150Open livid/v2ex/mapreduce/context.py/Context.__init__