code: private static boolean isIPv4MappedAddress(final byte[] addr) {
      if (addr.length < INADDR16SZ) {
        return false;
      }
      return addr[0] == 0x00 && addr[1] == 0x00 && addr[2] == 0x00 && addr[3] == 0x00
          && addr[4] == 0x00 && addr[5] == 0x00 && addr[6] == 0x00 && addr[7] == 0x00
          && addr[8] == 0x00 && addr[9] == 0x00 && addr[10] == (byte) 0xff && addr[11] == (byte) 0xff;
    }
docs: Utility routine to check if the InetAddress is an IPv4 mapped IPv6 address.
  
  @return a <code>boolean</code> indicating if the InetAddress is an IPv4 mapped IPv6 address; or
  false if address is IPv4 address.