    def add_args(parser):
        """Add model-specific arguments to the parser."""
        TransformerModel.add_args(parser)
        parser.add_argument(
            "--share-encoder-embeddings",
            action="store_true",
            help="share encoder embeddings across languages",
        )
        parser.add_argument(
            "--share-decoder-embeddings",
            action="store_true",
            help="share decoder embeddings across languages",
        )
        parser.add_argument(
            "--share-encoders",
            action="store_true",
            help="share encoders across languages",
        )
        parser.add_argument(
            "--share-decoders",
            action="store_true",
            help="share decoders across languages",
        )
Add model-specific arguments to the parser.
fairseq/models/multilingual_transformer.py