retval = None

    if isinstance(retval, str):

        return retval

    else:

        raise ValueError(f"not a valid string: {arg!r}")

def parse_arguments(arglist: Optional[Sequence[str]]=None) -> argparse.Namespace:

    parser = argparse.ArgumentParser(prog=PROGNAME)

    cliutil.add_version_argument(parser)

    cliutil.add_loglevel_argument(parser)

    parser.add_argument(

        '--delimiter', '-d',

        type=parse_delimiter,

        default='\\n',

        help="""String to output between links. Accepts all backslash escapes

""")

    parser.add_argument(

        '--zero', '--null', '-z', '-0',

        action='store_const',

        dest='delimiter',

        const='\0',

        help="""Shortcut for --delimiter=\\0

""")

    parser.add_argument(

        'odf_paths',

        metavar='ODF_PATH',

        type=Path,