def __call__(self):
        raise NotImplementedError('Filters must implement this method')
Correct handling of missing shard state.
dataset/ETHPy150Open arq5x/cyvcf/cyvcf/filters.py/Base.__call__--crossover with--dataset/ETHPy150Open GoogleCloudPlatform/appengine-mapreduce/python/test/mapreduce/handlers_test.py/MapperWorkerCallbackHandlerTest.testNoShardState