OrderedDict的JsonPickle子类不工作

import json
from collections import OrderedDict
import pickle

class OrderedJsonPickle(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, OrderedDict):
            return {'__ordered_dict__': True, 'items': list(obj.items())}
        return super().default(obj)

    def object_hook(self, dct):
        if '__ordered_dict__' in dct:
            return OrderedDict(dct['items'])
        return dct

def ordered_json_dumps(obj):
    return json.dumps(obj, cls=OrderedJsonPickle)

def ordered_json_loads(s):
    return json.loads(s, object_hook=OrderedJsonPickle().object_hook)

# 示例用法
data = OrderedDict([('key1', 'value1'), ('key2', 'value2')])
json_data = ordered_json_dumps(data)
print(json_data)  # 输出: {"__ordered_dict__": true, "items": [["key1", "value1"], ["key2", "value2"]]}
loaded_data = ordered_json_loads(json_data)
print(loaded_data)  # 输出: OrderedDict([('key1', 'value1'), ('key2', 'value2')])