public void ShouldCreateNewVectorWithNewValueAppended() { Vector <int> original = new ArrayVector <int>(1, 2, 3); original.ShouldList(1, 2, 3); Vector <int> appended = original.Append(4); original.ShouldList(1, 2, 3); appended.ShouldList(1, 2, 3, 4); }