docs: function (propertyName, newValue, oldValue) {
              this.$ActionWidget._onBoundPropertyChange.apply(this, arguments);
              var changedState = false;
              if (propertyName === "tooltip") {
                  this.getDom(); // makes sure _focusElt is defined
                  this._focusElt.title = newValue;
              }
              if (propertyName === "disabled") {
                  changedState = true;
                  this._isDisabled = !!newValue;
              }
              if (changedState) {
                  this._cfg[propertyName] = newValue;
                  this._updateState();
              }
          }