public void test(TestHarness harness)
{
JInternalFrame f = new JInternalFrame("F1");
harness.check(!f.isClosable());
f.addPropertyChangeListener(this);
f.setClosable(true);
harness.check(f.isClosable());
harness.check(lastEvent.getPropertyName(), "closable");
harness.check(lastEvent.getSource(), f);
harness.check(lastEvent.getOldValue(), Boolean.FALSE);