using System;

using System.Collections.Generic;

using System.Text;

using System.IO;

using System.Windows;

using System.Xml.Serialization;

​

public class Program  

{  

    public class Choobakka

    {

        public string Name { get; set; }

        [XmlIgnore]

        public VariableList<Item> Stuff { get; set; }

        [XmlArray("Stuff")]

        public Item[] _Stuff

        {

            get

            {

                return new Item[] {new Item() { Name = "1", Value = "111"}, new Item() { Name = "2", Value = "222"}};

            }

            set

            {

            }

        }

    }

    public class Item

    {

        public string Name { get; set; }

        public string Value { get; set; }

    }

    [XmlRoot("NewGroupName")]

    public sealed class VariableList<T> : List<T>

    {

        public new List<T> Items {get; set;}

        public new bool IsNull { get { return Items == null; } }

        public new bool IsEmpty { get { return IsNull || Count <= 0; } }

        public new int Count { get { return IsNull ? 0 : this.Items.Count; } }

        public new string CountAsString { get { return Count.ToString(); } }

        public VariableList()

        {

            Items = new List<T>();

        }

    }   

    public void Main()  

    {  

        var choobakka = new Choobakka() { Name = "CHOO-BAKKA", Stuff = new VariableList<Item>()  };            

        choobakka.Stuff.Items.Add( new Item() { Name = "passport", Value = "lv" } );

        choobakka.Stuff.Items.Add( new Item() { Name = "wallet", Value = "50euro" } );

        StringBuilder sb = new StringBuilder();

        using (var writer = new StringWriter(sb))

        {

            var xs = new XmlSerializer(typeof(Choobakka));

            xs.Serialize(writer, choobakka);

            Console.WriteLine(writer);

        }

    }    

} 

​