    @Test
    public void testDown() {

        final List<String> strs = new ArrayList<>();
        strs.addAll(Arrays.asList("my", "name", "is", "bascker"));
        sample.down(strs);
//        sample.down(nums);                        // 无法传入 List<Integer>
        final List<Object> objects = new ArrayList<>();
        objects.addAll(Arrays.asList(new Object(), new Object()));
        sample.down(objects);
    }