CodeObject.cs

using System.Collections;
using System.Collections.Specialized;
using System.Runtime.InteropServices;

namespace System.CodeDom
{
    [Serializable]
    [ClassInterface(ClassInterfaceType.AutoDispatch)]
    [ComVisible(true)]
    public class CodeObject
    {
        private IDictionary userData;

        public IDictionary UserData
        {
            get
            {
                if (userData == null)
                {
                    userData = new ListDictionary();
                }
                return userData;
            }
        }
    }
}