public void Change_Tail_Changes_Tail() { var newTail = A.Fake <IListNode <int> >(); var sut = new ListNode <int>(1, A.Fake <IListNode <int> >()); var result = sut.ChangeTail(newTail); Assert.That(result.Value, Is.EqualTo(sut.Value)); Assert.That(result.Tail, Is.EqualTo(newTail)); }