public void testCloning() {
        GrayPaintScale g1 = new GrayPaintScale();
        GrayPaintScale g2 = null;
        try {
            g2 = (GrayPaintScale) g1.clone();
        }
        catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        assertTrue(g1 != g2);
        assertTrue(g1.getClass() == g2.getClass());
        assertTrue(g1.equals(g2));