static RRule create(Freq freq, String until, int count, int interval,
        Map<ByRule, String> byRuleMap, Day wkst) {
      return builder()
          .freq(freq)
          .until(until)
          .count(count)
          .interval(interval)
          .byRuleMap(byRuleMap)
          .wkst(wkst)
          .build();
    }
A method for parsing an ExDate string in an {@link ExDate}

@param exDateString a string containing ExDate information, excluding the EXDATE prefix
@return an {@link ExDate}
portability-types-common/src/main/java/org/datatransferproject/types/common/models/calendar/RecurrenceRule.java