flag.set(true);
            }
        };

        assertFalse(flag.get());
        listener.onShutdown();
        assertTrue(flag.get());
    }

    public void test_shutdownListener_lambda() {
        // Test lambda implementation of ShutdownListener
        final AtomicBoolean flag = new AtomicBoolean(false);
        ShutdownListener listener = () -> flag.set(true);