src/transformers/commands/download.py/DownloadCommand/register_subcommand
class DownloadCommand:    def register_subcommand(parser: ArgumentParser):
        download_parser = parser.add_parser("download")
        download_parser.add_argument(
            "--cache-dir", type=str, default=None, help="Path to location to store the models"
        )
        download_parser.add_argument(
            "--force", action="store_true", help="Force the model to be download even if already in cache-dir"
        )
        download_parser.add_argument("model", type=str, help="Name of the model to download")
        download_parser.set_defaults(func=download_command_factory)