code: public static MinguoCalendar of(
          MinguoEra era,
          int yearOfEra,
          int month,
          int dayOfMonth
      ) {
  
          int prolepticYear = toProlepticYear(era, yearOfEra);
          PlainDate iso = PlainDate.of(prolepticYear, month, dayOfMonth);
          return new MinguoCalendar(iso);
  
      }
docs: /*[deutsch]
  <p>Erzeugt ein neues Minguo-Kalenderdatum. </p>
  
  @param   era         Minguo era
  @param   yearOfEra   Minguo year of era
  @param   month       gregorian month
  @param   dayOfMonth  day of month
  @return  new instance of {@code MinguoCalendar}
  @throws  IllegalArgumentException in case of any inconsistencies
  @since   3.13/4.10