MongoDB.Driver.Collection.Update C# (CSharp) Method

        public void Update(Document doc)
        {
            //Try to generate a selector using _id for an existing document.
            //otherwise just set the upsert flag to 1 to insert and send onward.
            Document selector = new Document();
            int upsert = 0;
            if(doc.Contains("_id")  & doc["_id"] != null){
                selector["_id"] = doc["_id"];
            }else{
                //Likely a new document
                doc.Prepend("_id",oidGenerator.Generate());
                upsert = 1;
            }
            this.Update(doc, selector, upsert);
        }