public void testCloning() {        
        XYSeries s1 = new XYSeries("Series");
        s1.add(1.2, 3.4);
        XYSeriesCollection c1 = new XYSeriesCollection();
        c1.addSeries(s1);
        IntervalXYDelegate d1 = new IntervalXYDelegate(c1);
        
        IntervalXYDelegate d2 = null;
        try {
            d2 = (IntervalXYDelegate) d1.clone();
        }
        catch (CloneNotSupportedException e) {
            System.err.println("Failed to clone.");
        }
        assertTrue(d1 != d2);
        assertTrue(d1.getClass() == d2.getClass());
        assertTrue(d1.equals(d2));