def copy(self, file_id):
Returns a unique string that satisifies the requirements for Django's
dataset/ETHPy150Open Net-ng/kansha/kansha/services/assetsmanager.py/AssetsManager.copy--crossover with--dataset/ETHPy150Open skibblenybbles/django-daydreamer/daydreamer/tests/views/behaviors/gzip/base.py/TestCase.unique_gzip