docs: public static Calendar toCalendar(final LocalDateTime self) {
          Calendar cal = Calendar.getInstance();
          cal.set(Calendar.DATE, self.getDayOfMonth());
          cal.set(Calendar.MONTH, self.getMonthValue() - 1);
          cal.set(Calendar.YEAR, self.getYear());
          cal.set(Calendar.HOUR_OF_DAY, self.getHour());
          cal.set(Calendar.MINUTE, self.getMinute());
          cal.set(Calendar.SECOND, self.getSecond());
          cal.set(Calendar.MILLISECOND, millisFromNanos(self.getNano()));
          return cal;
      }