@assure_container
    def download_object(self, container, obj, directory, structure=True):
        return container.download(obj, directory, structure=structure)
a pre-hook for the subclass
dataset/ETHPy150Open rackspace/pyrax/pyrax/object_storage.py/ContainerManager.download_object--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/test/test_hook.py/subPre