def test_is_empty_when_emptied():
q = Queue()
q.enqueue('spam')
q.enqueue('eggs')
q.dequeue()
q.dequeue()
expected = True
actual = q.is_empty()
assert actual == expected
def test_is_not_empty_when_full():
q = Queue()
q.enqueue('spam')
expected = False
actual = q.is_empty()
assert actual == expected
def test_queue_peek():
q = Queue()
q.enqueue('apples')
assert q.peek() == 'apples'