How to use the rdt.RDTClient function in rdt

metavar='FILENAME')
    options, args = parser.parse_args()
    if options.url is None:
        print('You must enter a url to download\n')
        parser.print_help()
        exit()
    if not options.file:
        options.file = re.search('[^/]*$', options.url).group(0)
    if not options.file or len(options.file) < 1:
        print('Invalid file name specified\n')
        parser.print_help()
        exit()

    log.startLogging(sys.stdout)
    factory = RTSPClientFactory(options.url, options.file)
    factory.protocol = RDTClient
    factory.bandwidth = 99999999999
    factory.deferred.addCallback(success).addErrback(error)
    reactor.connectTCP(factory.host, factory.port, factory)
    reactor.callLater(1, progress, factory)
    reactor.run()