public void onDestroy(PooledObject<TestComponent> p) {
                // Empty implementation
            }
        };

        factory.setOnDestroyListener(listener);
        assertSame(listener, factory.getOnDestroyListener());

        factory.setOnDestroyListener(null);
        assertNull(factory.getOnDestroyListener());
    }

    /**
     * Test multiple listener changes
     */