### Question:
ScheduledJobQueue implements Iterable<ScheduledJob> { @Override public synchronized Iterator<ScheduledJob> iterator() { Iterator<ScheduledJob> baseIterator = new ManyToOneIterator<>(myJobQueues.values(), myComparator); return new RunnableJobIterator(baseIterator); } ScheduledJobQueue(Comparator<ScheduledJob> comparator); synchronized void add(ScheduledJob job); synchronized void addAll(Collection<? extends ScheduledJob> jobs); synchronized void remove(ScheduledJob job); @Override synchronized Iterator<ScheduledJob> iterator();  }### Answer:
@Test public void testEmptyQueue() { assertThat(queue.iterator()).isEmpty(); }