MessageUnreadStatusVO(MessageUnreadStatusVO)

{
    "category": 0,
    "lastMessage": {
        "category": 0,
        "content": "string",
        "createTime": "2019-08-24T14:15:22.123Z",
        "id": 0,
        "isRead": true,
        "readTime": "2019-08-24T14:15:22.123Z",
        "receiveMode": 0,
        "receiverType": 0,
        "subject": {},
        "subjectKey": "string",
        "title": "string",
        "type": 0
    },
    "unReadCount": 0
}