@Test
  public void scheduleTest() {
    TestPriorityScheduler testScheduler = new TestPriorityScheduler();
    PrioritySchedulerDefaultPriorityWrapper psw =
        new PrioritySchedulerDefaultPriorityWrapper(testScheduler, TaskPriority.Low);
    psw.schedule(DoNothingRunnable.instance(), 10);
    assertTrue(testScheduler.scheduleCalled);

    // reset and try with priority
    testScheduler.scheduleCalled = false;
    psw.schedule(DoNothingRunnable.instance(), 10, TaskPriority.High);
    assertTrue(testScheduler.scheduleCalled);
  }