code: public final boolean isShowing(LocalDate startDate, LocalDate endDate, ZoneId zoneId) {
          return isShowing(this, startDate, endDate, zoneId);
      }
docs: Checks whether the entry will be visible within the given start and end dates. This method
  takes recurrence into consideration and will return true if any recurrence of this entry
  will be displayed inside the given time interval.
  
  @param startDate the start date of the search interval
  @param endDate   the end date of the search interval
  @param zoneId    the time zone
  @return true if the entry or any of its recurrences is showing