while (true) {
            val action = actions.poll() ?: break
            action(stream)
          }
        }
      }
      return@FutureTask null
    }
  }

  /** Returns once all stream actions complete successfully. */
  fun awaitSuccess() {
    val futureTask =
      results.poll(5, TimeUnit.SECONDS)
        ?: throw AssertionError("no onRequest call received")

    while (added < numElements) {
      // we could rely solely on #poll, but #drainTo might be more efficient when there are multiple
      // elements already available (e.g. LinkedBlockingQueue#drainTo locks only once)
      added += q.drainTo(buffer, numElements - added);
      if (added < numElements) { // not enough elements immediately available; will have to poll
        E e = q.poll(deadline - System.nanoTime(), NANOSECONDS);
        if (e == null) {

  }

  @Override
  public E take() throws InterruptedException {
    return delegate().take();
  }

  @Override
  @CheckForNull
  public E poll(long timeout, TimeUnit unit) throws InterruptedException {
    return delegate().poll(timeout, unit);
  }

  @Override
  public int drainTo(Collection<? super E> c) {
    return delegate().drainTo(c);
  }

  @Override

    sendRequest(methodName, arguments);
    Thread.sleep(DUE_DILIGENCE_MILLIS);
    assertEquals(true, invokeMethod("hasQueuedThread", this));
    assertNull(responseQueue.poll());
  }

  /**
   * Causes this thread to call the named method, and asserts that this thread thereby waits on the
   * given condition-like object. The lock-like object must have a method equivalent to {@link

  }

  @Override
  public E take() throws InterruptedException {
    return delegate().take();
  }

  @Override
  @CheckForNull
  public E poll(long timeout, TimeUnit unit) throws InterruptedException {
    return delegate().poll(timeout, unit);
  }

  @Override
  public int drainTo(Collection<? super E> c) {
    return delegate().drainTo(c);
  }

  @Override

            UrlQueue urlQueue;
            while ((urlQueue = urlQueueService.poll(sessionId1)) != null) {
                assertTrue(urlQueue.getUrl() + "=>" + url1, urlQueue.getUrl().startsWith(url1));
            }
            while ((urlQueue = urlQueueService.poll(sessionId2)) != null) {
                assertTrue(urlQueue.getUrl() + "=>" + url2, urlQueue.getUrl().startsWith(url2));
            }

    assertEquals(1, (int) mmHeap.peek());
    assertEquals(1, (int) mmHeap.poll());
    assertEquals(3, (int) mmHeap.peekLast());
    assertEquals(2, (int) mmHeap.peek());
    assertEquals(2, (int) mmHeap.poll());
    assertEquals(3, (int) mmHeap.peekLast());
    assertEquals(3, (int) mmHeap.peek());
    assertEquals(3, (int) mmHeap.poll());
    assertNull(mmHeap.peekLast());
    assertNull(mmHeap.peek());

    void insert(QUEUE urlQueue);

    void delete(String sessionId);

    void deleteAll();

    void offerAll(String sessionId, List<QUEUE> newUrlQueueList);

    QUEUE poll(String sessionId);

    void saveSession(String sessionId);

    boolean visited(QUEUE urlQueue);

    void generateUrlQueues(String previousSessionId, String sessionId);

          Object nextLabel;
          synchronized (PerListenerQueue.this) {
            Preconditions.checkState(isThreadScheduled);
            nextToRun = waitQueue.poll();
            nextLabel = labelQueue.poll();
            if (nextToRun == null) {
              isThreadScheduled = false;
              stillRunning = false;
              break;
            }
          }

    requestBodySinks.add(sink)
  }

  override fun isDuplex(): Boolean = true

  @Throws(InterruptedException::class)
  fun takeSink(): BufferedSink {
    return requestBodySinks.poll(5, SECONDS) ?: throw AssertionError("no sink to take")
  }

  fun assertNoMoreSinks() {
    assertTrue(requestBodySinks.isEmpty())
  }