docs: public int numOccurrences(int year, int month, int day) {
          DateTimeFormatter parser = ISODateTimeFormat.date();
          DateTime date = parser.parseDateTime(year + "-" + month + "-" + "01");
          Calendar cal = Calendar.getInstance();
          cal.setTime(date.toDate());
          GregorianChronology calendar = GregorianChronology.getInstance();
          DateTimeField field = calendar.dayOfMonth();
  
          int days = 0;
          int count = 0;
          int num = field.getMaximumValue(new LocalDate(year, month, day, calendar));
          while (days < num) {
              if (cal.get(Calendar.DAY_OF_WEEK) == day) {
                  count++;
              }
              date = date.plusDays(1);
              cal.setTime(date.toDate());
  
              days++;
          }
          return count;
      }