 Checkboxes and radio buttons should only use their value if they're
      // checked. Custom paper-checkbox and paper-radio-button elements
      // don't have a type, but they have the correct role set.
      if (this._usesCheckedInsteadOfValue(el))
        return el.checked;
      return true;
    },

    _doFakeSubmitForValidation: function() {
      var fakeSubmit = document.createElement('input');
      fakeSubmit.setAttribute('type', 'submit');
      fakeSubmit.style.display = 'none';
      this.appe