def test_append():
u"""Assert .append() adds a value to the t of the doubly linked list."""
doubly_linked = DoublyLinked()
for val in VALUES:
doubly_linked.append(val)
assert doubly_linked.tail.value == val
assert doubly_linked.tail.value == VALUES[-1]
def test_pop():
u"""Assert .pop() removes and returns the h value from the list."""
doubly_linked = DoublyLinked()
for val in VALUES:
doubly_linked.append(val)
for val in VALUES:
assert doubly_linked.pop() == val
assert doubly_linked.pop() is None
