code: @Override
      public boolean isIMMDate(final LocalDate date) {
          boolean same = false;
  
          final List<LocalDate> dates = getIMMDates(date.minusDays(1), date, QUARTERLY);
  
          if (!dates.isEmpty()) {
              same = date.equals(dates.get(0));
          }
  
          return same;
      }
docs: Checks if a given date is an official IMM Date (3rd Wednesdays of
  March/June/Sept/Dec.
  
  @param date
  @return true if that date is an IMM date.