code: function getCORSRequest() {
    var xhr = new root.XMLHttpRequest();
    if ('withCredentials' in xhr) {
      return xhr;
    } else if (!!root.XDomainRequest) {
      return new XDomainRequest();
    } else {
      throw new Error('CORS is not supported by your browser');
    }
  }
docs: Get CORS support even for older IE