final Queue<String> queue = new LinkedList<>();
        queue.add(text);
        final List<String> convertedTexts = new ArrayList<>(getMaxReadingNum());
        convertedTexts.add(text);

        for (final ReadingConverter converter : converters) {
            String s;
            while ((s = queue.poll()) != null && convertedTexts.size() <= getMaxReadingNum()) {

        .testForwarding(
            Queue.class,
            new Function<Queue, Queue>() {
              @Override
              public Queue apply(Queue delegate) {
                return wrap(delegate);
              }
            });
  }

  private static <T> Queue<T> wrap(Queue<T> delegate) {
    return new ForwardingQueue<T>() {
      @Override
      protected Queue<T> delegate() {
        return delegate;

  /**
   * Constructs a new finalizable soft reference.
   *
   * @param referent to softly reference
   * @param queue that should finalize the referent
   */
  protected FinalizableSoftReference(@Nullable T referent, FinalizableReferenceQueue queue) {
    super(referent, queue.queue);
    queue.cleanUp();
  }

  private final BlockingQueue<HttpUrl> queue;
  private final ConcurrentHashMap<String, AtomicInteger> hostnames = new ConcurrentHashMap<>();
  private final int hostLimit;

  public Crawler(OkHttpClient client, int queueLimit, int hostLimit) {
    this.client = client;
    this.queue = new LinkedBlockingQueue<>(queueLimit);
    this.hostLimit = hostLimit;
  }

  /** Returns the delay in nanoseconds until the next execution, or -1L to not reschedule. */
  abstract fun runOnce(): Long

  internal fun initQueue(queue: TaskQueue) {
    if (this.queue === queue) return

    check(this.queue === null) { "task is in multiple queues" }
    this.queue = queue
  }

  override fun toString(): String = name

  @CanIgnoreReturnValue
  public static Set<Feature<?>> addImpliedFeatures(Set<Feature<?>> features) {
    Queue<Feature<?>> queue = new ArrayDeque<>(features);
    while (!queue.isEmpty()) {
      Feature<?> feature = queue.remove();
      for (Feature<?> implied : feature.getImpliedFeatures()) {
        if (features.add(implied)) {
          queue.add(implied);
        }
      }
    }
    return features;
  }

  /**

      ReferenceQueue<Object> queue,
      PhantomReference<Object> frqReference) {
    this.queue = queue;

    this.finalizableReferenceClassReference = new WeakReference<>(finalizableReferenceClass);

    // Keep track of the FRQ that started us so we know when to stop.
    this.frqReference = frqReference;
  }

  /** Loops continuously, pulling references off the queue and cleaning them up. */

  /**
   * Schedules [task] for execution in [delayNanos]. A task may only have one future execution
   * scheduled. If the task is already in the queue, the earliest execution time is used.
   *
   * The target execution time is implemented on a best-effort basis. If another task in this queue
   * is running when that time is reached, that task is allowed to complete before this task is

  @CanIgnoreReturnValue
  public static Set<Feature<?>> addImpliedFeatures(Set<Feature<?>> features) {
    Queue<Feature<?>> queue = new ArrayDeque<>(features);
    while (!queue.isEmpty()) {
      Feature<?> feature = queue.remove();
      for (Feature<?> implied : feature.getImpliedFeatures()) {
        if (features.add(implied)) {
          queue.add(implied);
        }
      }
    }
    return features;
  }

  /**

  /** Returns the next entry in the access queue. */
  ReferenceEntry<K, V> getNextInAccessQueue();

  /** Sets the next entry in the access queue. */
  void setNextInAccessQueue(ReferenceEntry<K, V> next);

  /** Returns the previous entry in the access queue. */
  ReferenceEntry<K, V> getPreviousInAccessQueue();

  /** Sets the previous entry in the access queue. */