taskAttemptID[2] = job.findMapTask(trackers[2]);
clock.advance(5000);
job.finishTask(taskAttemptID[0]);
clock.advance(1000);
job.finishTask(taskAttemptID[1]);
clock.advanceBySpeculativeLag();
//we should get a speculative task now
job.refresh(clock.getTime());
taskAttemptID[3] = job.findMapTask(trackers[3]);