public void TestListPopBack()
{
CList <string> l1 = new CList <string>();
l1.Append("abcd");
l1.Append("qwerty");
l1.Append("hello");
l1.Append("world");
l1.PopBack();
Assert.AreEqual(l1.Length, 3);
Assert.AreEqual("[abcd, qwerty, hello]", l1.ToString());
}