MongoDB.Bson.Serialization.BsonClassMapSerializer.DeserializeExtraElement C# (CSharp) Метод

        private void DeserializeExtraElement(
            BsonReader bsonReader,
            object obj,
            string elementName,
            BsonMemberMap extraElementsMemberMap)
        {
            if (extraElementsMemberMap.MemberType == typeof(BsonDocument))
            {
                var extraElements = (BsonDocument)extraElementsMemberMap.Getter(obj);
                if (extraElements == null)
                {
                    extraElements = new BsonDocument();
                    extraElementsMemberMap.Setter(obj, extraElements);
                }
                var bsonValue = (BsonValue)BsonValueSerializer.Instance.Deserialize(bsonReader, typeof(BsonValue), null);
                extraElements[elementName] = bsonValue;
            }
            else
            {
                var extraElements = (IDictionary<string, object>)extraElementsMemberMap.Getter(obj);
                if (extraElements == null)
                {
                    if (extraElementsMemberMap.MemberType == typeof(IDictionary<string, object>))
                    {
                        extraElements = new Dictionary<string, object>();
                    }
                    else
                    {
                        extraElements = (IDictionary<string, object>)Activator.CreateInstance(extraElementsMemberMap.MemberType);
                    }
                    extraElementsMemberMap.Setter(obj, extraElements);
                }
                var bsonValue = (BsonValue)BsonValueSerializer.Instance.Deserialize(bsonReader, typeof(BsonValue), null);
                extraElements[elementName] = BsonTypeMapper.MapToDotNetValue(bsonValue);
            }
        }