@Override
    public int size() {
        lock.lock();
        try {
            return tasks.size();
        } finally {
            lock.unlock();
        }
    }
@Test
    void testSize() {
        assertEquals(0, nacosDelayTaskExecuteEngine.size());
        nacosDelayTaskExecuteEngine.addTask("test", abstractTask);
        assertEquals(1, nacosDelayTaskExecuteEngine.size());
        nacosDelayTaskExecuteEngine.removeTask("test");
        assertEquals(0, nacosDelayTaskExecuteEngine.size());
    }