@Override
  public boolean isRangeChanged(final int start, final int end) {
    LineStatusTracker<?> tracker = getTracker();
    if (tracker == null) {
      return false;
    }
    else {
      return tracker.isRangeModified(start, end);
    }
  }
@Override
  public boolean isRangeChanged(final int start, final int end)