public boolean equals(Object obj) {
   if (obj instanceof BERec) {
     BERec o = (BERec) obj;
     return when.equals(o.when) && task.equals(o.task) && event == o.event;
   }
   return false;
 }
 // make a BackgroundEvent for the task
 Schedule.BackgroundEvent bEvent(BackgroundTask task, Schedule.EventType event) {
   return new Schedule.BackgroundEvent(
       task, (event == Schedule.EventType.START ? task.getStart() : task.getFinish()), event);
 }
  public void testBackground() {
    final List rec = new ArrayList();
    TaskCallback cb =
        new TaskCallback() {
          public void taskEvent(SchedulableTask task, Schedule.EventType event) {
            rec.add(new BERec(Deadline.in(0), (BackgroundTask) task, event));
          }
        };
    assertFalse(tr.findTaskToRun());
    BackgroundTask t1 = btask(100, 200, .1, cb);
    BackgroundTask t2 = btask(100, 300, .2, cb);
    BackgroundTask t3 = btask(150, 200, .4, cb);

    Schedule s =
        sched(
            ListUtil.list(
                bEvent(t1, Schedule.EventType.START),
                bEvent(t2, Schedule.EventType.START),
                bEvent(t3, Schedule.EventType.START),
                bEvent(t1, Schedule.EventType.FINISH),
                bEvent(t3, Schedule.EventType.FINISH),
                bEvent(t2, Schedule.EventType.FINISH)));
    fact.setResults(ListUtil.list(s, s, s));

    assertTrue(tr.addToSchedule(t1));
    assertTrue(tr.addToSchedule(t2));
    assertTrue(tr.addToSchedule(t3));
    assertEquals(3, tr.getAcceptedTasks().size());
    assertIsomorphic(ListUtil.list(t1, t2, t3), tr.getAcceptedTasks());
    assertFalse(tr.findTaskToRun());
    assertEquals(0, rec.size());
    assertEquals(0, tr.getBackgroundLoadFactor(), .005);
    assertEquals(Deadline.at(100), tr.runningDeadline);

    TimeBase.setSimulated(101);
    assertFalse(tr.findTaskToRun());
    assertEquals(2, rec.size());
    assertEquals(.3, tr.getBackgroundLoadFactor(), .005);
    TimeBase.setSimulated(151);
    assertFalse(tr.findTaskToRun());
    assertEquals(3, rec.size());
    assertEquals(.7, tr.getBackgroundLoadFactor(), .005);
    assertEquals(3, tr.getAcceptedTasks().size());
    TimeBase.setSimulated(201);
    assertFalse(tr.findTaskToRun());
    assertEquals(5, rec.size());
    assertEquals(.2, tr.getBackgroundLoadFactor(), .005);
    assertEquals(1, tr.getAcceptedTasks().size());
    t2.taskIsFinished();
    TimeBase.setSimulated(202);
    assertFalse(tr.findTaskToRun());
    assertEquals(6, rec.size());
    assertEquals(0, tr.getBackgroundLoadFactor(), .005);
    assertEquals(0, tr.getAcceptedTasks().size());
    TimeBase.setSimulated(301);
    assertFalse(tr.findTaskToRun());
    assertEquals(6, rec.size());
    assertEquals(0, tr.getBackgroundLoadFactor(), .005);
    List exp =
        ListUtil.list(
            new BERec(101, t1, Schedule.EventType.START),
            new BERec(101, t2, Schedule.EventType.START),
            new BERec(151, t3, Schedule.EventType.START),
            new BERec(201, t1, Schedule.EventType.FINISH),
            new BERec(201, t3, Schedule.EventType.FINISH),
            new BERec(201, t2, Schedule.EventType.FINISH));
    assertEquals(exp, rec);
  }