@Override
  public void setComparator(Comparator comparator) {
    // the comparator is used for sorting rendered choices, and for
    // comparison operations on the text parser
    if ((comparator != this.comparator) && (comparator != null)) {
      this.comparator = comparator;
      formatOrComparatorUpdated();
    }
  }
@Override
  public void setComparator(Comparator comparator)