docs: function () {
                  if (this._hasPlaceholder) {
                      var element = this._domElt;
                      var cssClass = new aria.utils.ClassList(element);
                      element.value = "";
                      this._hasPlaceholder = false;
                      cssClass.remove('placeholder');
                      cssClass.$dispose();
                      this._domElt.unselectable = "off";
                  }
              }