code: public Iterator<ISO9660Directory> sortedIterator() {
          if (sortedIterator == null) {
              sortedIterator = new ISO9660DirectoryIterator(this, true);
          }
          sortedIterator.reset();
          return sortedIterator;
      }
docs: Returns a directory iterator to traverse the directory hierarchy according to the needs of ISO 9660 (sort order
  of Path Tables and Directory Records)
  
  @return Iterator