code: private SortedSet<Date> filterExceptions(SortedSet<Date> dates) {
  
          SortedSet<Date> result = new TreeSet<Date>();
          for (Date d : dates) {
              if (!m_exceptions.contains(d)) {
                  result.add(d);
              }
          }
          return result;
      }
docs: Filters all exceptions from the provided dates.
  @param dates the dates to filter.
  @return the provided dates, except the ones that match some exception.