@base.resource(downloads.Download)
    def download(self, download_id):
        return downloads.Downloads(self, download_id)
mutate a copy of the given feature set
dataset/ETHPy150Open ducksboard/libsaas/libsaas/services/github/repos.py/Repo.download--crossover with--dataset/ETHPy150Open ceteri/exelixi/src/uow.py/UnitOfWorkFactory.mutate_features