def test_basic_single_thread_2(self):
		q = PersistentQueueWithAcknowledgement("test_queue.fs")
		for i in xrange(10):
			q.put(BW(Something(i)))

		myset = set()
		items = []

		while not q.empty():
			i = q.get()
			myset.add(i)
			items.append(i)

		# ack last 5 items
		for item in items[4:]:
			q.ack(item)
			myset.remove(item)


		# Check that all elements are on the nonack queue and no elements is on the main queue
		self.assertTrue(len(q._queue.elements.items()) == 0)

		# Check that five elements are on the nonack set
		nonack_set = set()
		for item in q._nonack_queue.keys():
			nonack_set.add(item)

		self.assertEqual(myset, nonack_set)