MongoDB.Bson.IO.BsonWriter.WriteNull C# (CSharp) Method

        public abstract void WriteNull();

        public override void Serialize(BsonWriter bsonWriter, Type nominalType, object value, IBsonSerializationOptions options)
        {
            if (value == null)
            {
                bsonWriter.WriteNull();
                return;
            }
            var metaObject = ((IDynamicMetaObjectProvider)value).GetMetaObject(Expression.Constant(value));
            var memberNames = metaObject.GetDynamicMemberNames().ToList();
            if (memberNames.Count == 0)
            {
                bsonWriter.WriteNull();
                return;
            }

            bsonWriter.WriteStartDocument();
            foreach (var memberName in memberNames)
            {
                bsonWriter.WriteName(memberName);
                var memberValue = BinderHelper.GetMemberValue(value, memberName);
                if (memberValue == null)
                    bsonWriter.WriteNull();
                else
                {
                    var memberType = memberValue.GetType();
                    var serializer = BsonSerializer.LookupSerializer(memberType);
                    serializer.Serialize(bsonWriter, memberType, memberValue, options);
                }
            }
            bsonWriter.WriteEndDocument();
        }