{

    "_id" : ObjectId("57baba1ce4b039915181cf08"),

    "_class" : "com.myapp.entity.ActivityEntity",

    "act" : "ORDER_CUSTOMER",

    "use" : "momo",

    "oCstM" : "57baba1ce4b039915181cf07",

    "creDt" : ISODate("2016-08-22T08:38:52.300Z"),

    "ord" : {

        "$ref" : "order",

        "$id" : ObjectId("57b6a733e4b03991517a5332")

    }

}