action='store_const', const='::', dest='source_address',
help='Make all connections via IPv6 (experimental)',
)
+ network.add_option(
+ '--cn-verification-proxy',
+ dest='cn_verification_proxy', default=None, metavar='URL',
+ help='Use this proxy to verify the IP address for some Chinese sites. '
+ 'The default proxy specified by --proxy (or none, if the options is not present) is used for the actual downloading. (experimental)'
+ )
selection = optparse.OptionGroup(parser, 'Video Selection')
selection.add_option(