[alibaba/fastjson]为什么 map的value是byte[]，并且我在ParserConfig注册了byte[]的反序列化器，但是却没有调用到?

json string -> java byte[] 仅支持内置的base64？

package com.l1yp;

import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.parser.ParserConfig;
import com.alibaba.fastjson.serializer.SerializeConfig;
import com.l1yp.util.JsonTool;
import com.qq.protocol.pb.ByteArrayDeserializer;
import com.qq.protocol.pb.serializer.ByteArraySerializer;

import java.util.Arrays;
import java.util.Map;

/**
 * @Author Lyp
 * @Date 2020/7/11
 * @Email l1yp@qq.com
 */
public class FastjsonTest {

    private static class User {
        public Map<String, byte[]> key;
    }

    public static void main(String[] args) {
        ParserConfig.getGlobalInstance().putDeserializer(byte[].class, new ByteArrayDeserializer());
        String json = """
                {"key": {"data":"01020304"}}
                """;
        User user1 = JSONObject.parseObject(json, User.class);
        System.out.println("user1 = " + user1);
    }

}

public class ByteArrayDeserializer implements ObjectDeserializer {

    @Override
    public <T> T deserialze(DefaultJSONParser parser, Type type, Object fieldName) {
        if (type == byte[].class){
            return (T) HexUtil.hex2bin(parser.getLexer().stringVal());
        }
        throw new UnsupportedOperationException("不支持的类型");
    }

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