docs: public static PeriodType yearDayTime() {
          PeriodType type = cYDTime;
          if (type == null) {
              type = new PeriodType(
                  "YearDayTime",
                  new DurationFieldType[] {
                      DurationFieldType.years(), DurationFieldType.days(),
                      DurationFieldType.hours(), DurationFieldType.minutes(),
                      DurationFieldType.seconds(), DurationFieldType.millis(),
                  },
                  new int[] { 0, -1, -1, 1, 2, 3, 4, 5, }
              );
              cYDTime = type;
          }
          return type;
      }