def keys(self, argv):
        keys = self._obj.keys()
        self._print_list(map(repr, keys))
        return keys
Get download strategy based on the destination object.
dataset/ETHPy150Open kdart/pycopia/fepy/pycopia/fepy/CLI.py/DictCLI.keys--crossover with--dataset/ETHPy150Open GoogleCloudPlatform/gsutil/gslib/copy_helper.py/_SelectDownloadStrategy