Serialization in C# driver of MongoDB

gistfile1.cs

using System;
using System.Collections.Generic;
using MongoDB.Bson;
using MongoDB.Bson.Serialization.Attributes;
using MongoDB.Bson.Serialization.Options;
using MongoDB.Driver;

namespace TestMongoDot
{
    class MyEntity
    {
        public ObjectId Id { get; set; }
        public string Name { get; set; }

        // NOTE :
        // Ensure dictionary is serilize as Document, if you 
        // want query like "something.something".
        // Or it will *automatically" serilize as array, if your
        // key contains a "." or "$"
        //
        // Reference : https://github.com/mongodb/mongo-csharp-driver/blob/master/MongoDB.DriverUnitTests/Linq/SelectDictionaryTests.cs
        //
        [BsonDictionaryOptions(DictionaryRepresentation.Document)]
        public Dictionary<string, string> mydict;
    }

    class Program
    {
        static void Main(string[] args)
        {
            var connStr = "mongodb://localhost";
            var mgClient = new MongoClient(connStr);
            var mgServer = mgClient.GetServer();

            var db = mgServer.GetDatabase("test");

            var coll = db.GetCollection<MyEntity>("myDotEntity");

            var ent = new MyEntity {Name = "Jacky"};
            var dict = new Dictionary<string, string>();
            dict["hello.haha"] = "world";
            ent.mydict = dict;

            coll.Insert(ent);
            var id = ent.Id;

            Console.WriteLine(id);
        }
    }
}