def test_q_peek():
q = Queue()
q.enqueue("apple")
q.enqueue("banana")
actual = q.q_peek()
expected = "apple"
assert actual == expected
def test_peek_empty():
q = Queue()
with pytest.raises(InvalidOperationError) as e:
q.q_peek()
assert str(e.value) == "Not allowed on empty structure"
