    def add_args(parser):
        """Add model-specific arguments to the parser."""
        TransformerModel.add_args(parser)
        parser.add_argument(
            "--pretrained-xlm-checkpoint",
            type=str,
            metavar="STR",
            help="XLM model to use for initializing transformer encoder and/or decoder",
        )
        parser.add_argument(
            "--init-encoder-only",
            action="store_true",
            help="if set, don't load the XLM weights and embeddings into decoder",
        )
        parser.add_argument(
            "--init-decoder-only",
            action="store_true",
            help="if set, don't load the XLM weights and embeddings into encoder",
        )
Add model-specific arguments to the parser.
fairseq/models/transformer_from_pretrained_xlm.py