def METHOD_NAME(self, parser):
    for name in ("run", "variants"):
        subparser = parser.subcommands.choices.get(name, None)
        if subparser is None:
            continue
        subparser.add_argument_group("CIT varianter options")
        settings.register_option(
            section=f"{name}.cit",
            key="parameter_file",
            metavar="PATH",
            help_msg="Paths to a parameter file",
            parser=subparser,
            default=None,
            long_arg="--cit-parameter-file",
        )
        help_msg = "Order of combinations. Maximum number is 6"
        settings.register_option(
            section=f"{name}.cit",
            key="combination_order",
            key_type=int,
            parser=subparser,
            help_msg=help_msg,
            metavar="ORDER",
            default=DEFAULT_ORDER_OF_COMBINATIONS,
            long_arg="--cit-order-of-combinations",
        )