Very often, we need to simply look up a document by _id. What we have to do is use findOne() and updateOne() with eq("_id", <id value>). Since there's no official constant for "_id" we also have to define our own constant. This seems like something that can be easily provided in an official capacity. Ideally, this would be methods in MongoCollection like findById(<id value>), updateOneById(<id value>, <update>), and so on.