code: public boolean isIPv4CompatibleAddress() {
          if ((ipaddress[0] == 0x00) && (ipaddress[1] == 0x00) &&
              (ipaddress[2] == 0x00) && (ipaddress[3] == 0x00) &&
              (ipaddress[4] == 0x00) && (ipaddress[5] == 0x00) &&
              (ipaddress[6] == 0x00) && (ipaddress[7] == 0x00) &&
              (ipaddress[8] == 0x00) && (ipaddress[9] == 0x00) &&
              (ipaddress[10] == 0x00) && (ipaddress[11] == 0x00))  {
              return true;
          }
          return false;
      }
docs: Utility routine to check if the InetAddress is an
  IPv4 compatible IPv6 address.
  
  @return a <code>boolean</code> indicating if the InetAddress is
  an IPv4 compatible IPv6 address; or false if address is IPv4 address.
  @since 1.4