[QUESTION]JSON.toJSONString方法使用Filter后，子属性对象中的@type会缺失

使用JSON.toJSONString生成json时，用下面的方法会使子属性中的@type缺失，父属性中@type正常输出
JSON.toJSONString(epgUserVo, new Filter[]{ TOKEN_USER_PROPERTY_FILTER }, JSONWriter.Feature.WriteClassName)

{
"@type": "com.kd.epg.domain.vo.user.BaseEpgUserVo",
"endDate": "2023-10-10 22:32:28",
"epgInfoVo": {
"back_hall_url": "",
"TokenExpiretime": "20230926153828"....
}
}

epgInfoVo是子属性类,继承自HashMap，正常应该有 "@type":"com.kd.epg.domain.vo.user.impl.GuangxiEpgInfoVo"，但是这里不会生成

去除filter后子属性的@type正常添加了：
JSON.toJSONString(epgUserVo, JSONWriter.Feature.WriteClassName)

{
"@type": "com.kd.epg.domain.vo.user.BaseEpgUserVo",
"endDate": "2023-10-10 22:50:36",
"epgInfoVo": {
"@type": "com.kd.epg.domain.vo.user.impl.GuangxiEpgInfoVo",
"back_hall_url": "",
"TokenExpiretime": "20230926153828".....
}
}

filter内容
PropertyFilter TOKEN_USER_PROPERTY_FILTER = (object, name, value) -> {
if ("epg_info".equals(name)) return false;
return true;
};

这个情况是否正常，或者正确写法应该是如何？

Start by reproducing the issue with JSON.toJSONString(epgUserVo, new Filter[]{ TOKEN_USER_PROPERTY_FILTER }, JSONWriter.Feature.WriteClassName), then compare it with serialization without the filter. Check how the PropertyFilter handling affects the nested epgInfoVo type metadata; done means determining whether the missing @type is expected or correcting the behavior and verifying the result.

Written by the indexing model from the issue text.