start = System.currentTimeMillis();
        SerializeUtil.serialize(hmap);
        System.out.println("HashMap serialize:" + (System.currentTimeMillis() - start));

        start = System.currentTimeMillis();
        SerializeUtil.serialize(amap);
        System.out.println("ArrayMap serialize:" + (System.currentTimeMillis() - start));
    }

    private static class MyKey {