@Override
  protected List<DateTimeField> validFields() {

    DateTimeField[] array = { NANO_OF_SECOND, NANO_OF_DAY, MICRO_OF_SECOND, MICRO_OF_DAY, MILLI_OF_SECOND,
        MILLI_OF_DAY, SECOND_OF_MINUTE, SECOND_OF_DAY, MINUTE_OF_HOUR, MINUTE_OF_DAY, CLOCK_HOUR_OF_AMPM, HOUR_OF_AMPM,
        CLOCK_HOUR_OF_DAY, HOUR_OF_DAY, AMPM_OF_DAY, DAY_OF_WEEK, ALIGNED_DAY_OF_WEEK_IN_MONTH,
        ALIGNED_DAY_OF_WEEK_IN_YEAR, DAY_OF_MONTH, DAY_OF_YEAR, EPOCH_DAY, ALIGNED_WEEK_OF_MONTH, ALIGNED_WEEK_OF_YEAR,
        MONTH_OF_YEAR, EPOCH_MONTH, YEAR_OF_ERA, YEAR, ERA, OFFSET_SECONDS, INSTANT_SECONDS, JulianDayField.JULIAN_DAY,
        JulianDayField.MODIFIED_JULIAN_DAY, JulianDayField.RATA_DIE, };
    return Arrays.asList(array);
  }