assertFalse(executor.isTerminated());

    // WAIT #2
    barrier.await(1, SECONDS);
    assertFalse(executor.awaitTermination(20, MILLISECONDS));

    // WAIT #3
    barrier.await(1, SECONDS);
    assertTrue(executor.awaitTermination(1, SECONDS));
    assertTrue(executor.awaitTermination(0, SECONDS));
    assertTrue(executor.isShutdown());

    assertFalse(executor.isTerminated());

    // WAIT #2
    barrier.await(1, SECONDS);
    assertFalse(executor.awaitTermination(20, MILLISECONDS));

    // WAIT #3
    barrier.await(1, SECONDS);
    assertTrue(executor.awaitTermination(1, SECONDS));
    assertTrue(executor.awaitTermination(0, SECONDS));
    assertTrue(executor.isShutdown());

// Execute concurrently
crawler1.setBackground(true);
crawler2.setBackground(true);

String sessionId1 = crawler1.execute();
String sessionId2 = crawler2.execute();

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

### Custom Interval Control

```java
// Configure politeness policy
container.singleton("intervalController", DefaultIntervalController.class, controller -> {

  protected ForwardingExecutorService() {}

  @Override
  protected abstract ExecutorService delegate();

  @CheckReturnValue
  @Override
  public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException {
    return delegate().awaitTermination(timeout, unit);
  }

  @Override
  public <T extends @Nullable Object> List<Future<T>> invokeAll(

            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;

  public void testDelegations() throws InterruptedException {
    MockExecutor mock = new MockExecutor();
    TestExecutor testExecutor = new TestExecutor(mock);
    assertFalse(testExecutor.awaitTermination(10, MILLISECONDS));
    mock.assertLastMethodCalled("awaitTermination");
    assertFalse(testExecutor.isTerminated());
    mock.assertLastMethodCalled("isTerminated");
    assertFalse(testExecutor.isShutdown());

  public void testDelegations() throws InterruptedException {
    MockExecutor mock = new MockExecutor();
    TestExecutor testExecutor = new TestExecutor(mock);
    assertFalse(testExecutor.awaitTermination(10, MILLISECONDS));
    mock.assertLastMethodCalled("awaitTermination");
    assertFalse(testExecutor.isTerminated());
    mock.assertLastMethodCalled("isTerminated");
    assertFalse(testExecutor.isShutdown());

  protected ForwardingExecutorService() {}

  @Override
  protected abstract ExecutorService delegate();

  @CheckReturnValue
  @Override
  public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException {
    return delegate().awaitTermination(timeout, unit);
  }

  @Override
  public <T extends @Nullable Object> List<Future<T>> invokeAll(

      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
  }

  /**
   * Invokes {@code executor.}{@link ExecutorService#awaitTermination(long, TimeUnit)
   * awaitTermination(long, TimeUnit)} uninterruptibly with no timeout.
   *
   * @since 30.0
   */
  @J2ktIncompatible
  @GwtIncompatible // concurrency

        parentThread.start();
        if (!background) {
            awaitTermination();
        }
        return crawlerContext.sessionId;
    }

    /**
     * Waits for the crawling process to terminate indefinitely.
     */
    public void awaitTermination() {
        awaitTermination(0);
    }

    /**
     * Waits for the crawling process to terminate for a specified duration.