@Test
public void testFetchHead() throws IOException, ExecutorManagerException,
    InterruptedException {

  final QueuedExecutions queue = new QueuedExecutions(5);
  final List<Pair<ExecutionReference, ExecutableFlow>> dataList = getDummyData();
  Assert.assertTrue(queue.isEmpty());
  queue.enqueueAll(dataList);
  Assert.assertEquals(queue.fetchHead(), dataList.get(0));
  Assert.assertEquals(queue.fetchHead(), dataList.get(1));
}