r i = 0; i < elements.length; i++) {
          var values = this._serializeElementValues(elements[i]);
          for (var v = 0; v < values.length; v++) {
            this._addSerializedElement(json, elements[i].name, values[v]);
          }
        }
        return json;
      },

      _handleFormResponse: function (event) {
        this.fire('iron-form-response', event.detail);
      },

      _handleFormError: function (event) {
        this.fire('iron-form-error', event.detail);
      },

      _makeAj