assertSame(tb, beanRegistry.getSingleton("tb"));
assertEquals(1, beanRegistry.getSingletonCount());
String[] names = beanRegistry.getSingletonNames();
assertEquals(1, names.length);
assertEquals("tb", names[0]);
assertFalse(tb.wasDestroyed());
beanRegistry.destroySingletons();
assertEquals(0, beanRegistry.getSingletonCount());
assertEquals(0, beanRegistry.getSingletonNames().length);
assertTrue(tb.wasDestroyed());