public void Copy()
{
StringStack copy = _stack.Copy();
Assert.AreEqual(_stack.Count, copy.Count);
int count = _stack.Count;
for (int i = 0; i < count; i++)
{
CloneableType x = _stack.Pop(), y = copy.Pop();
Assert.AreEqual(x, y);
Assert.AreNotSame(x, y);
}
}