}

    @Override
    public T call() throws Exception {
      return delegate.call();
    }
  }

  private static final class WrappedRunnable implements Runnable {
    private final Runnable delegate;

    WrappedRunnable(Runnable delegate) {
      this.delegate = delegate;
    }

    @Override
    public void run() {
      delegate.run();
    }
  }

  }

  public void testToString() {
    Runnable[] currentTask = new Runnable[1];
    Executor delegate =
        new Executor() {
          @Override
          public void execute(Runnable task) {
            currentTask[0] = task;
            task.run();
            currentTask[0] = null;
          }

          @Override
          public String toString() {

    }

    @Override
    public T call() throws Exception {
      return delegate.call();
    }
  }

  private static final class WrappedRunnable implements Runnable {
    private final Runnable delegate;

    WrappedRunnable(Runnable delegate) {
      this.delegate = delegate;
    }

    @Override
    public void run() {
      delegate.run();
    }
  }

   * to any {@code Runnable} passed to the default implementation of {@link #wrapTask(Runnable)}.
   */
  protected abstract <T extends @Nullable Object> Callable<T> wrapTask(Callable<T> callable);

  /**
   * Wraps a {@code Runnable} for submission to the underlying executor. The default implementation
   * delegates to {@link #wrapTask(Callable)}.
   */
  protected Runnable wrapTask(Runnable command) {

// instead of using an AtomicReferenceFieldUpdater. This reference stores Thread instances
// and DONE/INTERRUPTED - they have a common ancestor of Runnable.
abstract class InterruptibleTask<T extends @Nullable Object>
    extends AtomicReference<@Nullable Runnable> implements Runnable {
  static {
    // Prevent rare disastrous classloading in first call to LockSupport.park.
    // See: https://bugs.openjdk.org/browse/JDK-8074773

   */
  @CanIgnoreReturnValue // TODO(kak): consider removing this
  @Override
  protected final <T extends @Nullable Object> RunnableFuture<T> newTaskFor(
      Runnable runnable, @ParametricNullness T value) {
    return TrustedListenableFutureTask.create(runnable, value);
  }

  /**
   * @since 19.0 (present with return type {@code ListenableFutureTask} since 14.0)
   */
  @CanIgnoreReturnValue // TODO(kak): consider removing this

   * Runnable}, and arrange that {@code get} will return the given result on successful completion.
   *
   * @param runnable the runnable task
   * @param result the result to return on successful completion. If you don't need a particular
   *     result, consider using constructions of the form: {@code ListenableFuture<?> f =
   *     ListenableFutureTask.create(runnable, null)}
   */

   * Executor Ever.
   *
   * @author cbiffle
   */
  public static class FakeExecutor implements Executor {
    List<Runnable> tasks = new ArrayList<>();

    @Override
    public void execute(Runnable task) {
      tasks.add(task);
    }

    public List<Runnable> getTasks() {
      return tasks;
    }
  }

  }

  private static class ForwardingRunnable implements Runnable {

    private final Runnable runnable;

    ForwardingRunnable(Runnable runnable) {
      this.runnable = runnable;
    }

    @Override
    public void run() {
      runnable.run();
    }

    @Override
    public String toString() {
      return runnable.toString();
    }
  }

  private interface Adder {

  private val busyQueues = mutableListOf<TaskQueue>()

  /** Queues not in [busyQueues] that have non-empty [TaskQueue.futureTasks]. */
  private val readyQueues = mutableListOf<TaskQueue>()

  private val runnable: Runnable =
    object : Runnable {
      override fun run() {
        var task: Task =
          withLock {
            runCallCount++
            awaitTaskToRun()
          } ?: return