Returns the IPv6 addresses associated with this NIC. If no IPv6
        addresses are used, empty dict is returned.

def _get_ipv6addrs(self):
        """
        Returns the IPv6 addresses associated with this NIC. If no IPv6
        addresses are used, empty dict is returned.
        """
        addrs = self._get_addrs()
        ipv6addrs = addrs.get(netifaces.AF_INET6)
        if not ipv6addrs:
            return {}
        return ipv6addrs[0]