stack.addLast(new NodeAndRemainingSuccessors<>(startNode));

    while (!stack.isEmpty()) {
      // To peek at the top two items, we need to temporarily remove one.
      NodeAndRemainingSuccessors<N> top = stack.removeLast();
      NodeAndRemainingSuccessors<N> prev = stack.peekLast();
      stack.addLast(top);

      N node = top.node;
      N previousNode = prev == null ? null : prev.node;

    stack.addLast(new NodeAndRemainingSuccessors<>(startNode));

    while (!stack.isEmpty()) {
      // To peek at the top two items, we need to temporarily remove one.
      NodeAndRemainingSuccessors<N> top = stack.removeLast();
      NodeAndRemainingSuccessors<N> prev = stack.peekLast();
      stack.addLast(top);

      N node = top.node;
      N previousNode = prev == null ? null : prev.node;

        header.next.remove();
        return first;
    }

    /**
     * Removes the last element.
     *
     * @return the last element
     */
    public E removeLast() {
        if (isEmpty()) {
            throw new NoSuchElementException();
        }
        final E last = header.previous.element;
        header.previous.remove();
        return last;
    }

    Deque<Spliterator<T>> splits = new ArrayDeque<>();
    splits.addLast(stream.spliterator());

    while (!splits.isEmpty()) {
      Spliterator<T> spliterator = splits.removeLast();

      if (spliterator.getExactSizeIfKnown() == 0) {
        continue; // drop this split
      }

      // Many spliterators will have trySplits that are SUBSIZED even if they are not themselves

        override fun runOnce(): Long {
          log += "run@${taskFaker.nanoTime}"
          if (schedules.isNotEmpty()) {
            redQueue.schedule(this, schedules.removeAt(0))
          }
          return delays.removeAt(0)
        }
      }
    redQueue.schedule(task, 100.µs)

    taskFaker.advanceUntil(0.µs)
    assertThat(log).isEmpty()

    taskFaker.advanceUntil(100.µs)

    takeIndex = inc(takeIndex);
    --count;
    return x;
  }

  /**
   * Utility for remove and iterator.remove: Delete item at position i. Call only when occupying
   * monitor.
   */
  void removeAt(int i) {
    E[] items = this.items;
    // if removing front item, just advance
    if (i == takeIndex) {
      items[takeIndex] = null;
      takeIndex = inc(takeIndex);
    } else {

      if (value == 8) {
        iter.remove();
      }
    }
    assertIntact(q);
    assertThat(result).containsExactly(1, 15, 13, 8, 14);
  }

  /**
   * This tests a special case of the removeAt() call. Moving an element sideways on the heap could
   * break the invariants. Sometimes we need to bubble an element up instead of trickling down. See
   * implementation.
   */
  public void testInvalidatingRemove() {

      }

      return result
    } finally {
      peekedHeader = null
      limit = pushedLimit
      constructed = pushedConstructed
      if (name != null) path.removeAt(path.size - 1)
    }
  }

  /**
   * Execute [block] with a new namespace for type hints. Type hints from the enclosing type are no
   * longer usable by the current type's members.
   */

  private fun startNextTask(): SerialTask? {
    taskRunner.assertLockHeld()

    val index = serialTaskQueue.indexOfFirst { it.isReady() }
    if (index == -1) return null

    val nextTask = serialTaskQueue.removeAt(index)
    currentTask = nextTask
    contextSwitchCount++
    nextTask.start()
    return nextTask
  }

  private interface SerialTask {
    /** Returns true if this task is ready to start. */

    }
    for (i in readyQueues.size - 1 downTo 0) {
      val queue = readyQueues[i]
      queue.cancelAllAndDecide()
      if (queue.futureTasks.isEmpty()) {
        readyQueues.removeAt(i)
      }
    }
  }

  interface Backend {
    fun nanoTime(): Long

    fun coordinatorNotify(taskRunner: TaskRunner)

    fun coordinatorWait(
      taskRunner: TaskRunner,