While properties like IPv6Address.is_private account for IPv4-mapped
IPv6 addresses, such as for example:
>>> ipaddress.ip_address("192.168.0.1").is_private
True
>>> ipaddress.ip_address("::ffff:192.168.0.1").is_private
True
...the same doesn't currently apply to the is_loopback property:
>>> ipaddress.ip_address("127.0.0.1").is_loopback
True
>>> ipaddress.ip_address("::ffff:127.0.0.1").is_loopback
False
At minimum, this inconsistency between different properties is
counter-intuitive. Moreover, ::ffff:127.0.0.0/104 is for all intents and
purposes a loopback address, and should be treated as such.
