public void ready() {
        sync.releaseShared(UNUSED);
    }
@Test
  public void testStartingGunInterruptions() throws InterruptedException {
    StartingGun sg = new StartingGun();
    Thread[] threads = startWaitingThreads(sg);

    Thread.sleep(PAUSE);

    allThreadsAlive(threads);

    for (Thread thread : threads) thread.interrupt();

    Thread.sleep(PAUSE);

    sg.ready();

    allThreadsDead(threads);
  }