val taskRunner: TaskRunner =
    TaskRunner(
      object : TaskRunner.Backend {
        override fun execute(
          taskRunner: TaskRunner,
          runnable: Runnable,
        ) {
          taskRunner.assertLockHeld()

          val queuedTask = RunnableSerialTask(runnable)
          serialTaskQueue += queuedTask
          executeCallCount++
          isParallel = serialTaskQueue.size > 1
        }

      return true;
    }

    @Override
    public void execute(Runnable runnable) {}

    @Override
    public <V> ListenableScheduledFuture<V> schedule(
        Callable<V> callable, long delay, TimeUnit unit) {
      return NeverScheduledFuture.create();
    }

    @Override
    public ListenableScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) {
      return NeverScheduledFuture.create();

  }

  /** The number of elements to place in collections, arrays, etc. */
  static final int SIZE = 20;

  /** Returns a new started daemon Thread running the given runnable. */
  final Thread newStartedThread(Runnable runnable) {
    Thread t = new Thread(runnable);
    t.setDaemon(true);
    t.start();
    return t;
  }

  /**
   * Waits for the specified time (in milliseconds) for the thread to terminate (using {@link

            throw e;
        }
    }

    /**
     * Execute a runnable through the circuit breaker
     *
     * @param runnable the runnable to execute
     * @throws Exception if execution fails or circuit is open
     */
    public void run(Runnable runnable) throws Exception {
        call(() -> {
            runnable.run();
            return null;
        });
    }

    /**

  public void addListener(Runnable listener, Executor executor) {
    checkNotNull(listener, "Runnable was null.");
    checkNotNull(executor, "Executor was null.");
    try {
      executor.execute(listener);
    } catch (Exception e) { // sneaky checked exception
      // ListenableFuture's contract is that it will not throw unchecked exceptions, so log the bad
      // runnable and/or executor and swallow it.
      log.get()

          public String get(long time, TimeUnit unit) {
            throw new CancellationException(); // BAD!!
          }

          @Override
          public void addListener(Runnable runnable, Executor executor) {
            executor.execute(runnable);
          }
        };
    future.setFuture(badFuture);
    ExecutionException expected = getExpectingExecutionException(future);

  private abstract static class FailToForward extends ForwardingObject implements Runnable {
    @Override
    public void run() {}
  }

  private abstract static class ForwardToDelegate extends ForwardingObject implements Runnable {
    @Override
    public void run() {
      delegate().run();
    }

    @Override
    protected abstract Runnable delegate();
  }

  }

  @CanIgnoreReturnValue
  public B withSetUp(Runnable setUp) {
    this.setUp = setUp;
    return self();
  }

  public Runnable getSetUp() {
    return setUp;
  }

  @CanIgnoreReturnValue
  public B withTearDown(Runnable tearDown) {
    this.tearDown = tearDown;
    return self();
  }

  public Runnable getTearDown() {
    return tearDown;
  }

  // Features

  }

  @Override
  public <T> ListenableFuture<T> submit(Runnable task, T result) {
    Preconditions.checkNotNull(task, "task must not be null!");
    Preconditions.checkNotNull(result, "result must not be null!");
    return delegate.submit(task, result);
  }

  @Override
  public ListenableFuture<?> submit(Runnable task) {
    Preconditions.checkNotNull(task, "task must not be null!");

  }

  @Override
  public <T> ListenableFuture<T> submit(Runnable task, T result) {
    Preconditions.checkNotNull(task, "task must not be null!");
    Preconditions.checkNotNull(result, "result must not be null!");
    return delegate.submit(task, result);
  }

  @Override
  public ListenableFuture<?> submit(Runnable task) {
    Preconditions.checkNotNull(task, "task must not be null!");