final String key = "bar";

    // start computing thread
    new Thread() {
      @Override
      public void run() {
        result.set(0, cache.getUnchecked(key));
        doneSignal.countDown();
      }
    }.start();

    // wait for computation to start
    secondSignal.await();

    // start waiting thread
    new Thread() {
      @Override

    final String key = "bar";

    // start computing thread
    new Thread() {
      @Override
      public void run() {
        result.set(0, cache.getUnchecked(key));
        doneSignal.countDown();
      }
    }.start();

    // wait for computation to start
    secondSignal.await();

    // start waiting thread
    new Thread() {
      @Override