code: function getActiveRegionTypeCode(item) {
    // We always put the region first, and at most one is active.
    var activeRegions = item._concepts[0].activeItems;
    if (activeRegions.length === 1) {
      return activeRegions[0].code;
    }
  }
docs: Returns the active regiontype code, eg. SA4, or undefined if none _or more than one_ active.