code: function _updateWorkingSetState() {
          if (MainViewManager.getPaneCount() === 1 &&
                  MainViewManager.getWorkingSetSize(MainViewManager.ACTIVE_PANE) === 0) {
              $workingSetViewsContainer.hide();
              $gearMenu.hide();
          } else {
              $workingSetViewsContainer.show();
              $gearMenu.show();
          }
      }
docs: Update state of working set
  @private