如何使用monogoengine更新文档的字典字段键？

from mongoengine import Document, StringField, DictField

class MyDocument(Document):
    my_dict = DictField()

document = MyDocument.objects.get(id='document_id')

document.my_dict['new_key'] = document.my_dict.pop('old_key')

document.save()

from mongoengine import Document, StringField, DictField

class MyDocument(Document):
    my_dict = DictField()

document = MyDocument.objects.get(id='document_id')
document.my_dict['new_key'] = document.my_dict.pop('old_key')
document.save()