public void testDisposableBean() {
DefaultSingletonBeanRegistry beanRegistry = new DefaultSingletonBeanRegistry();
DerivedTestBean tb = new DerivedTestBean();
beanRegistry.registerSingleton("tb", tb);
beanRegistry.registerDisposableBean("tb", tb);
assertSame(tb, beanRegistry.getSingleton("tb"));
assertSame(tb, beanRegistry.getSingleton("tb"));
assertEquals(1, beanRegistry.getSingletonCount());