public void if_peak_the_last_elemet_of_stack_the_stack_still_contain_it()
{
var stack = new LajtiStack();
stack.Push(456);
stack.Push(999);
var result1 = stack.Peek();
var result2 = stack.Peek();
Assert.That(result1, Is.EqualTo(999));
Assert.That(result2, Is.EqualTo(999));
}
public void when_the_stack_is_epty_then_the_peek_equal_to_exeption()
{
var stack = new LajtiStack();
Assert.Throws <InvalidOperationException>(() => stack.Peek());
}