def test_linked_list_append():
    ll = LinkedList()
    ll.head = Node(1)
    ll.head.next = Node(2)
    ll.append(3)
    assert ll.head.next.next.value == 3
    assert ll.head.next.next.next == None
def test_linked_list_append():
    """Test a value can be appended to a linked list."""

    linked_list = LinkedList()
    value = 1
    linked_list.insert(value)

    value = 2
    linked_list.append(value)
    assert linked_list.head.next.value == value
    assert linked_list.head.next.next == None

    value = 3
    linked_list.append(value)
    assert linked_list.head.next.next.value == value
    assert linked_list.head.next.next.next == None