{
    "type": "object",
    "properties": {
        "_id": {
            "type": "string"
        },
        "_ctime": {
            "type": "string"
        },
        "_mtime": {
            "type": "string"
        }
    },
    "required": [
        "_id",
        "_ctime",
        "_mtime"
    ],
    "version": 1
}