protected void notifyListeners(ChartChangeEvent event) {
        if (this.notify) {
            Object[] listeners = this.changeListeners.getListenerList();
            for (int i = listeners.length - 2; i >= 0; i -= 2) {
                if (listeners[i] == ChartChangeListener.class) {
                    ((ChartChangeListener) listeners[i + 1]).chartChanged(
                            event);