code: function() {
              var aLength = this._panels.length;
              var bAllClosed = true;
              for(var i=0;i<aLength;i++) {
                  if(YUD.hasClass(this._panels[i].firstChild, this.CLASSES.ACTIVE)) {
                      this._panels[i].firstChild.tabIndex = 0;
                      bAllClosed = false;
                  }
                  else {
                      this._panels[i].firstChild.tabIndex = -1;
                  }
              }
              if(bAllClosed) {
                  this._panels[0].firstChild.tabIndex = 0;
              }
              // now everything is done so we can fire the stateChanged event
              this.fireEvent(stateChangedEvent);
          }
docs: Set tabIndex to 0 on the first item in case all panels are closed
  or active. Otherwise set it to -1
  @method _fixTabIndexes
  @private