def addPyfeynOptions(parser):
    """Add the PyFeyn options to the options parser's option set."""
    parser.add_option('-V', '--visual-debug', dest='VDEBUG', action=
        'store_true', default=False, help='produce visual debug output')
    parser.add_option('-D', '--debug', dest='DEBUG', action='store_true',
        default=False, help='produce debug output')
    parser.add_option('-d', '--draft', dest='DRAFT', action='store_true',
        default=False, help=
        'produce draft output, skipping time-consuming calculations')
    return parser
