[Test] public void testDup() { GenericStack <string> stringStack = new GenericStack <string>(); stringStack.Dup(); Assert.AreEqual(0, stringStack.Count); stringStack.Push("value 1"); stringStack.Push("value 2"); stringStack.Dup(); Assert.AreEqual(3, stringStack.Count); Assert.AreEqual("value 2", stringStack.Peek(0)); Assert.AreEqual("value 2", stringStack.Peek(1)); Assert.AreEqual("value 1", stringStack.Peek(2)); }