def test_str():
list = LinkedList()
list.insert(3)
list.insert(5)
list.insert(7)
list.insert(9)
assert list.__str__() == "{ 9 } -> { 7 } -> { 5 } -> { 3 } -> NULL"
def test_insert_multi():
list = LinkedList()
list.insert(3)
list.insert(5)
list.insert(7)
list.insert(9)
assert list.head.value == 9
assert list.head.next.value == 7
assert list.head.next.next.value == 5
assert list.head.next.next.next.value == 3
assert list.head.next.next.next.next == None
def test_append():
list = LinkedList()
list.insert(1)
list.insert(2)
list.append(3)
assert list.head.next.next.value == 3
def test_includes_false():
list = LinkedList()
list.insert(7)
list.insert(9)
assert list.includes(5) == False
def test_includes_true():
list = LinkedList()
list.insert(7)
list.insert(9)
assert list.includes(9) == True
def test_head():
list = LinkedList()
list.insert(3)
assert list.head.value == 3