public void ItemKeyInt32()
        {
            Int32StringList list = new Int32StringList(item => item.Key);

            list.Add(new Int32Keyed(2, "two"));
            Assert.AreEqual(new Int32Keyed(2, "two"), ((ListEx <Int32Keyed>)list)[0]);
            Assert.AreEqual(new Int32Keyed(2, "two"), list[2]);
            Assert.AreEqual(new Int32Keyed(2, "two"), list.GetByKey(2));
        }
        public void ItemKeyInt32()
        {
            Int32StringList list = new Int32StringList();

            list.Add(2, "two");
            Assert.AreEqual(new Int32StringPair(2, "two"), ((ListEx <Int32StringPair>)list)[0]);
            Assert.AreEqual(new CloneableType("two"), list[2]);
            Assert.AreEqual(new CloneableType("two"), list.GetByKey(2));
        }