我有用户模型和评论，我用django\u elasticsearch\u dsl来索引elasticsearch

# models.py

class Comment(models.Model):
  user = models.OneToOneField(User, on_delete=models.CASCADE)
  reply_type =  models.JSONField(default=dict)
``` `reply_type` 内容

reply_type: {
"one": "on... ...",
"two": "tw... ..."
}

我是这样做的

documents.py

@registry.register_document
class UserDocument(Document):
email = fields.TextField()
username = fields.TextField()
first_name = fields.TextField()
...
...
...

comment = fields.NestedField(properties={
    # other fields...
    'some_field': fields.TextField(),
    'reply_type': fields.ObjectField(),
})    

class Index:
    name = 'user'
    settings = {
        'number_of_shards': 1,
        'number_of_replicas': 0
    }

class Django:
    model = User

问题是当我做索引的时候 `reply_type` 是空的

"reply_type": [
{ },
{ }
]

有什么建议吗？