def key(self, entity_id):
    return db.Key.from_path("TestEntity", entity_id)
Given an event source mapping ID or an event source ARN and FunctionName,
dataset/ETHPy150Open GoogleCloudPlatform/appengine-mapreduce/python/test/mapreduce/handlers_test.py/MapreduceHandlerTestBase.key--crossover with--dataset/ETHPy150Open saltstack/salt/salt/modules/boto_lambda.py/event_source_mapping_exists