public void testCloning() {
        KeyedObjects ko1 = new KeyedObjects();
        ko1.addObject("V1", new Integer(1));
        ko1.addObject("V2", null);
        ko1.addObject("V3", new Integer(3));
        KeyedObjects ko2 = null;
        try {
            ko2 = (KeyedObjects) ko1.clone();
        }
        catch (CloneNotSupportedException e) {
            System.err.println("Failed to clone.");
        }
        assertTrue(ko1 != ko2);
        assertTrue(ko1.getClass() == ko2.getClass());
        assertTrue(ko1.equals(ko2));