@Override
  public int hashCode() {
    return jobId.hashCode() * 524287 + id;
  }
@Test
  public void testHashCode() {
    TaskType[] types = TaskType.values();

    for (int i = 0; i < types.length; i++) {
      JobID jobId = new JobID("1234" + i, i);
      TaskID taskId1 = new TaskID(jobId, types[i], i);
      TaskID taskId2 = new TaskID(jobId, types[i], i);

      assertTrue("The hashcode() method gave unequal hash codes for two equal "
          + "task IDs", taskId1.hashCode() == taskId2.hashCode());
    }
  }