code: function send() {
  
          this.request.open(this.method, this.url);
  
          for (var header in this.headers) {
              this.request.setRequestHeader(header, this.headers[header]);
          }
  
          var str_data = '';
  
          if (this.data instanceof FormData) {
              this.request.send(this.data);
          } else {
              for (var name in this.data) {
                  str_data = str_data + name + '=' + encodeURIComponent(this.data[name]) + '&';
              }
              this.request.send(str_data);
          }
      }
docs: Should be called on instance created with factory Ajax.create() method
  Opens request, applies headers, builds data URL encoded string and sends request