def test_insert_after_last():
    list = LinkedList()
    list.append(1)
    list.append(2)
    list.append(3)
    list.insertAfter(3, 3.5)
    assert list.head.next.next.next.value == 3.5
def test_insert_after_middle():
    list = LinkedList()
    list.append(1)
    list.append(2)
    list.append(3)
    list.insertAfter(2, 2.5)
    assert list.head.next.next.value == 2.5