}
  }

  enum Impl {
    NEW {
      @Override
      <T> Facade<T> newFacade() {
        return new NewAbstractFutureFacade<T>();
      }
    },
    OLD {
      @Override
      <T> Facade<T> newFacade() {
        return new OldAbstractFutureFacade<T>();
      }
    };

    abstract <T> Facade<T> newFacade();
  }

  @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.

  public Object measureSize() {
    for (Thread thread : blockedThreads) {
      thread.interrupt();
    }
    blockedThreads.clear();
    Facade<Object> f = impl.newFacade();
    for (int i = 0; i < numThreads; i++) {
      Thread thread =
          new Thread() {
            @Override
            public void run() {
              try {
                f.get();