def METHOD_NAME(parser):
    """Add task-specific arguments to the parser."""
    # fmt: off
    TranslationTask.METHOD_NAME(parser)
    parser.add_argument('--langs', required=True, metavar='LANG',
                        help='comma-separated list of monolingual language, '
                             'for example, "en,de,fr". These should match the '
                             'langs from pretraining (and be in the same order). '
                             'You should always add all pretraining language idx '
                             'during finetuning.')
    parser.add_argument('--prepend-bos', action='store_true',
                        help='prepend bos token to each sentence, which matches '
                             'mBART pretraining')
    # fmt: on