ShutdownListener listener = () -> flag.set(true);

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

    @Test
    public void test_shutdownListener_exceptionHandling() {
        // Test exception thrown in shutdown listener
        jobExecutor.addShutdownListener(new ShutdownListener() {
            @Override
            public void onShutdown() {