def test_repr():
ll = DoublyLinkedList()
assert (repr(ll) == "Empty")
for i in range(5):
ll.insert_tail(i)
assert(repr(ll) == "0 {data: 0} <-> 1 {data: 1} <-> "\
"2 {data: 2} <-> 3 {data: 3} <-> 4 {data: 4}")
def test_insert_tail():
ll = DoublyLinkedList()
for i in range(ITERS):
ll.insert_tail(i)
assert (len(ll) == i + 1)
assert (ll.peek_tail() == i)
def base_ll():
ll = DoublyLinkedList()
for i in range(ITERS):
ll.insert_tail(i)
return ll
