Implementation of BsonDocument backed class

MongoDocument.cs

using System;
 
using MongoDB.Bson;
using MongoDB.Bson.Serialization;
using MongoDB.Bson.Serialization.Attributes;
 
[Serializable]
[BsonSerializer(typeof(MongoDocumentClassSerializer))]
public class MongoDocument : BsonDocumentBackedClass
{
    public MongoDocument()
        : base(new MongoDocumentClassSerializer())
    {
    }
 
    public MongoDocument(BsonDocument backingDocument)
        : base(backingDocument, new MongoDocumentClassSerializer())
    {
    }
 
    public MongoDocument(BsonDocument backingDocument, IBsonDocumentSerializer serializer)
        : base(backingDocument, serializer)
    {
 
    }
 
    [BsonId]
    public ObjectId Id { get; set; }
 
    public BsonValue this[string fieldname]
    {
        get
        {
            return this.BackingDocument[fieldname];
        }
 
        set
        {
            this.BackingDocument[fieldname] = value;
        }
    }
 
    public static implicit operator BsonDocument(MongoDocument document)
    {
        return document.BackingDocument;
    }
}