    @Test
    public void testPark() {

        Thread thread = new Thread(() -> {
            out.println("启动测试");
            LockSupport.park();
            out.println("unpack了");
        });
        thread.start();
        LockSupport.parkNanos(TimeUnit.SECONDS.toNanos(6));
        LockSupport.unpark(thread);
    }