code: function _convertSortPref(sortMethod) {
          if (!sortMethod) {
              return null;
          }
  
          if (_sortPrefConversionMap.hasOwnProperty(sortMethod)) {
              sortMethod = _sortPrefConversionMap[sortMethod];
              PreferencesManager.setViewState(_WORKING_SET_SORT_PREF, sortMethod);
          } else {
              sortMethod = null;
          }
  
          return sortMethod;
      }
docs: Converts the old brackets working set sort preference into the modern paneview sort preference
  @private
  @param {!string} sortMethod - sort preference to convert
  @return {?string} new sort preference string or undefined if an sortMethod is not found