@Override
    public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {}
  }

  /**
   * A CyclicBarrier that uses timed await and fails with AssertionFailedErrors instead of throwing
   * checked exceptions.
   */
  public class CheckedBarrier extends CyclicBarrier {
    public CheckedBarrier(int parties) {
      super(parties);
    }

    @Override
    public int await() {