[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));
}
