{
"_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")
}
}