def counter(self, counter_name, default=0):
    return self.shard_context.counter(counter_name, default)
Serialize a queryset.
dataset/ETHPy150Open GoogleCloudPlatform/appengine-mapreduce/python/src/mapreduce/map_job_context.py/SliceContext.counter--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/django/core/serializers/base.py/Serializer.serialize