getSecondaryCalendarType = () => {
    if (secondaryCalendarType === undefined) {
      secondaryCalendarType = (0, _InitialConfiguration.getSecondaryCalendarType)();
    }
    if (secondaryCalendarType && secondaryCalendarType in _CalendarType.default) {
      return secondaryCalendarType;
    }
    return secondaryCalendarType;
  }
Returns the configured secondary calendar type.
@public
@returns { CalendarType | undefined } the effective calendar type
@since 1.18.0