*
   * @param ip {@link Inet6Address} to be examined for ISATAP address format
   * @return {@code true} if the argument is an ISATAP address
   */
  public static boolean isIsatapAddress(Inet6Address ip) {

    // If it's a Teredo address with the right port (41217, or 0xa101)
    // which would be encoded as 0x5efe then it can't be an ISATAP address.
    if (isTeredoAddress(ip)) {

            );

    for (String validIsatapAddress : validIsatapAddresses) {
      InetAddress ip = InetAddresses.forString(validIsatapAddress);
      assertTrue(InetAddresses.isIsatapAddress((Inet6Address) ip));
      assertWithMessage("checking '%s'", validIsatapAddress)
          .that(InetAddresses.getIsatapIPv4Address((Inet6Address) ip))
          .isEqualTo(ipv4);
    }