Map<String, Object> parentMap = new LinkedHashMap<>();
        DocMap docMap = new DocMap(parentMap);

        docMap.put("c_key", "value_c");
        docMap.put("a_key", "value_a");
        docMap.put("lang", "en");
        docMap.put("b_key", "value_b");

        Set<Map.Entry<String, Object>> entrySet = docMap.entrySet();

            while (iter.hasNext()) {
                final String _key = (String) iter.next();
                final int _klen = _key.length();
                boolean match = false;

                if (_klen == key.length()) {
                    match = _key.equals(key);
                } else if (_klen < key.length()) {
                    match = _key.regionMatches(0, key, 0, _klen) && key.charAt(_klen) == '\\';
                }

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

    private static class MyKey {
        Object _key;

        MyKey(Object key) {
            _key = key;
        }

        @Override
        public int hashCode() {
            return 0;
        }

        @Override
        public boolean equals(Object o) {