public static void addShutdownHook(Runnable runnable) {
        Runtime.getRuntime().addShutdownHook(new Thread(runnable));
    }
@Test
    void testAddShutdownHook() {
        Runnable shutdownHook = () -> {
        };
        ThreadUtils.addShutdownHook(shutdownHook);
        // It seems no way to check it.
    }