def __init__(self, mapreduce_spec, shard_state):
    """Constructor.

    Args:
      mapreduce_spec: mapreduce specification as model.MapreduceSpec.
      shard_state: shard state as model.ShardState.
    """
    # 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.

    Args:
      mapreduce_spec: mapreduce specification as model.MapreduceSpec.
      shard_state: shard state as model.ShardState.
    
mapreduce/context.py