GroupChatMessage

{
    "content": {
        "description": "string",
        "displayname": "string",
        "title": "string",
        "username": "string"
    },
    "created_at": 0,
    "direction": "string",
    "file_url": null,
    "from_avatar": "string",
    "from_id": "string",
    "from_name": "string",
    "id": 0,
    "original_id": "string",
    "room_ext_id": "string",
    "text_content": "string",
    "time": 0,
    "type": "\"text\"",
    "updated_at": 0
}