}

  @Override
  public boolean isTerminated() {
    return delegate.isTerminated();
  }

  @Override
  public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException {
    Preconditions.checkNotNull(unit, "unit must not be null!");
    return delegate.awaitTermination(timeout, unit);
  }

  @Override
  public <T> ListenableFuture<T> submit(Callable<T> task) {

  }

  @Override
  public boolean isTerminated() {
    return delegate.isTerminated();
  }

  @Override
  public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException {
    Preconditions.checkNotNull(unit, "unit must not be null!");
    return delegate.awaitTermination(timeout, unit);
  }

  @Override
  public <T> ListenableFuture<T> submit(Callable<T> task) {

            assertEquals(CrawlerStatus.RUNNING, crawler1.crawlerContext.getStatus());
            assertEquals(CrawlerStatus.RUNNING, crawler2.crawlerContext.getStatus());

            crawler1.awaitTermination();
            crawler2.awaitTermination();

            assertEquals(maxCount, dataService.getCount(sessionId1));
            assertEquals(maxCount, dataService.getCount(sessionId2));

            UrlQueue urlQueue;

    assertThat(future2.isDone()).isFalse();

    // Stop the first task. The second task should then run.
    blockingCallable.stop();
    executor.shutdown();
    assertThat(executor.awaitTermination(10, SECONDS)).isTrue();
    assertThat(getDone(future2)).isFalse();
  }

  public void testSecondTaskWaitsForFirstEvenIfCancelled() throws Exception {
    BlockingCallable blockingCallable = new BlockingCallable();

                if (!dataCrawlingThreadList.get(i).isRunning() && Constants.RUNNING.equals(dataCrawlingThreadStatusList.get(i))) {
                    dataCrawlingThreadList.get(i).awaitTermination();
                    dataCrawlingThreadStatusList.set(i, Constants.DONE);
                    activeCrawlerNum--;
                }
            }
            ThreadUtil.sleep(crawlingExecutionInterval);

    assertTrue(future.isDone());

    assertTrue(successLatch.await(200, MILLISECONDS));
    assertTrue(listenerLatch.await(200, MILLISECONDS));

    latch.countDown();

    exec.shutdown();
    exec.awaitTermination(100, MILLISECONDS);
  }

  /**
   * Tests that all listeners complete, even if they were added before or after the future was

      aa.set(i, (double) COUNTDOWN);
    }
    Counter c1 = new Counter(aa);
    Counter c2 = new Counter(aa);
    Thread t1 = newStartedThread(c1);
    Thread t2 = newStartedThread(c2);
    awaitTermination(t1);
    awaitTermination(t2);
    assertEquals(SIZE * COUNTDOWN, c1.counts + c2.counts);
  }

  /** a deserialized serialized array holds same values */
  public void testSerialization() throws Exception {

            assertEquals(CrawlerStatus.RUNNING, crawler1.crawlerContext.getStatus());
            assertEquals(CrawlerStatus.RUNNING, crawler2.crawlerContext.getStatus());

            crawler1.awaitTermination();
            crawler2.awaitTermination();

            assertEquals(maxCount, dataService.getCount(sessionId1));
            assertEquals(maxCount, dataService.getCount(sessionId2));

            UrlQueue urlQueue;

    @Override
    public boolean isShutdown() {
      return false;
    }

    @Override
    public boolean isTerminated() {
      return false;
    }

    @Override
    public boolean awaitTermination(long timeout, TimeUnit unit) {
      return false;
    }
  }

    @Override
    public boolean isShutdown() {
      return false;
    }

    @Override
    public boolean isTerminated() {
      return false;
    }

    @Override
    public boolean awaitTermination(long timeout, TimeUnit unit) {
      return false;
    }
  }