repeatedlyInterruptTestThread(20, tearDownStack);
    thread.joinUnsuccessfully(70);
    assertInterrupted();
  }

  // sleep() Tests
  public void testSleepNoInterrupt() {
    sleepSuccessfully(10);
  }

  public void testSleepSingleInterrupt() {
    requestInterruptIn(10);
    sleepSuccessfully(50);
    assertInterrupted();
  }