public void testCloneIndependence() {
        DefaultKeyedValueDataset d1 
            = new DefaultKeyedValueDataset("Key", new Double(10.0));
        DefaultKeyedValueDataset d2 = null;
        try {
            d2 = (DefaultKeyedValueDataset) d1.clone();
        }
        catch (CloneNotSupportedException e) {
            System.err.println("Failed to clone.");
        }
        assertTrue(d1.equals(d2));
        d2.updateValue(new Double(99.9));
        assertFalse(d1.equals(d2));
        d2.updateValue(new Double(10.0));
        assertTrue(d1.equals(d2));