using System; using System.Collections.Generic; public class Test { public static int Main () { MySystem mySystem = new MySystem (); return 0; } public static void TestFunction (IEnumerable<string> items) { List<string> newList; Console.WriteLine ("1"); newList = new List<string> (items); Console.WriteLine ("2"); newList = new List<string> (items); } } public class MySystem { private List<string> _items = new List<string> (); public MySystem () { _items.Add ("a"); } public IEnumerable<string> Items { get { foreach (string i in _items) { Console.WriteLine (i); yield return i; } } } }