@Test
  public void submitCallableTest() {
    TestPriorityScheduler testScheduler = new TestPriorityScheduler();
    PrioritySchedulerDefaultPriorityWrapper psw =
        new PrioritySchedulerDefaultPriorityWrapper(testScheduler, TaskPriority.Low);
    psw.submit(new TestCallable());
    assertTrue(testScheduler.submitCallableCalled);

    // reset and try with priority
    testScheduler.submitCallableCalled = false;
    psw.submit(new TestCallable(), TaskPriority.High);
    assertTrue(testScheduler.submitCallableCalled);
  }