// Mladi, o.z. IPv6/IPv4 research
(function(){
  var a6 = new XMLHttpRequest();
  a6.open('GET', 'https://6.is.ipv6.sk/96f20e45-a527-42dc-a224-e481645f852b', true);
  a6.send(null);

  var a4 = new XMLHttpRequest();
  a4.open('GET', 'https://4.is.ipv6.sk/96f20e45-a527-42dc-a224-e481645f852b', true);
  a4.send(null);
})();