register_options(
      [
        OptPath.new('LOCAL_PAC', [false, 'Local PAC file.' ]),
        OptString.new('REMOTE_PAC', [false, 'Remote PAC file. (Ex: http://192.168.1.20/proxy.pac)' ]),
        OptBool.new('DISABLE_PROXY', [true, 'Disable the proxy server.', false]),