public void testCloning() {
        StackedAreaRenderer r1 = new StackedAreaRenderer();
        StackedAreaRenderer r2 = null;
        try {
            r2 = (StackedAreaRenderer) r1.clone();
        }
        catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        assertTrue(r1 != r2);
        assertTrue(r1.getClass() == r2.getClass());
        assertTrue(r1.equals(r2));