code: public static boolean isValid(
          EastAsianYear year,
          EastAsianMonth month,
          int dayOfMonth
      ) {
  
          int cycle = year.getCycle();
          int yearOfCycle = year.getYearOfCycle().getNumber();
          return CALSYS.isValid(cycle, yearOfCycle, month, dayOfMonth);
  
      }
docs: /*[deutsch]
  <p>Pr&uuml;ft, ob die angegebenen Parameter ein wohldefiniertes Kalenderdatum beschreiben. </p>
  
  @param   year        the year to be checked
  @param   month       the month to be checked
  @param   dayOfMonth  the day of month to be checked
  @return  {@code true} if valid else {@code false}