var c = new List<Item>
        {
          new Item {Id = "1", Price = 10, Flag = MyFlag.Jedna},
          new Item {Id = "1", Price = 12, Flag = MyFlag.Dva},
          new Item {Id = "2", Price = 10, Flag = MyFlag.Jedna},
          new Item {Price = 20, Flag = MyFlag.Jedna},
          new Item {Price = 30, Flag = MyFlag.Jedna},
        };