    def add_args(parser):
        """Add model-specific arguments to the parser."""
        parser.add_argument(
            "--input-feat-per-channel",
            type=int,
            metavar="N",
            help="encoder input dimension per input channel",
        )
        parser.add_argument(
            "--in-channels",
            type=int,
            metavar="N",
            help="number of encoder input channels",
        )
        parser.add_argument(
            "--conv-enc-config",
            type=str,
            metavar="EXPR",
            help="""
    an array of tuples each containing the configuration of one conv layer
    [(out_channels, kernel_size, padding, dropout), ...]
            """,
        )
Add model-specific arguments to the parser.
examples/speech_recognition/models/w2l_conv_glu_enc.py