
        if (el.tagName.toLowerCase() === 'select' && el.multiple) {
          for (var o = 0; o < el.options.length; o++) {
            if (el.options[o].selected) {
              addSerializedElement(el.name, el.options[o].value);
            }
          }
        } else {
          addSerializedElement(el.name, el.value);
        }
      }

      return json;
    },

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

    _handleFormError: function (ev