def test_linked_prepend_2():
    l = DoubleLinkedList()
    l.prepend(5)
    l.prepend(7)
    assert l.front.value == 7
    assert l.front.next.value == 5
    assert l.end.value == 5
    assert_contains(l, [7, 5])
def test_linked_prepend():
    l = DoubleLinkedList()
    l.prepend(5)
    assert l.front.value == 5
    assert l.end.value == 5
    assert_contains(l, [5])