def validate_ipv6_addr(value)
      ipaddr = IPAddr.new(value)
      unless ipaddr.ipv6?
        raise ValidationError, "IP address '#{value}' is not IPv6"
      end
      ipaddr
    rescue ArgumentError => e
      raise ValidationError, "invalid IPv6 address '#{value}' - #{e.message}"
    end
def validate_ipv6_addr(value)
      ipaddr = IPAddr.new(value)
      unless ipaddr.ipv6?
        raise ValidationError, "IP address '#{value}' is not IPv6"
      end
      ipaddr
    rescue ArgumentError => e
      raise ValidationError, "invalid IPv6 address '#{value}' - #{e.message}"
    end
Validate that the given string _value_ describes a well-formed
 IPV6 network address using the standard "ipaddr" ruby module.