    def add_args(cls, parser):
        """Add model-specific arguments to the parser."""
        dc = getattr(cls, "__dataclass", None)
        if dc is not None:
            # do not set defaults so that settings defaults from various architectures still works
            gen_parser_from_dataclass(parser, dc(), delete_default=True)
Add model-specific arguments to the parser.
fairseq/models/fairseq_model.py