}

    boolean hasNext() {
      return !tasks.isEmpty();
    }

    void runNext() {
      assertTrue("expected at least one task to run", hasNext());
      tasks.remove().run();
    }

    void runAll() {
      while (hasNext()) {
        runNext();
      }
    }
  }

  private FakeExecutor fakePool;
  private SequentialExecutor e;

  @Override
  public void setUp() {

    }

    boolean hasNext() {
      return !tasks.isEmpty();
    }

    void runNext() {
      assertTrue("expected at least one task to run", hasNext());
      tasks.remove().run();
    }

    void runAll() {
      while (hasNext()) {
        runNext();
      }
    }
  }

  private FakeExecutor fakePool;
  private SequentialExecutor e;

  @Override
  public void setUp() {

            }
        }

        final StringBuilder resultBuf = new StringBuilder(100);
        final boolean runAll = webConfigIds == null && fileConfigIds == null && dataConfigIds == null;

        if (sessionId == null) { // create session id
            final SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");

     */
    public void crawl(final String sessionId, final List<String> webConfigIdList, final List<String> fileConfigIdList) {
        final boolean runAll = webConfigIdList == null && fileConfigIdList == null;
        final List<WebConfig> webConfigList;
        if (runAll || webConfigIdList != null) {
            webConfigList = ComponentUtil.getCrawlingConfigHelper().getWebConfigListByIds(webConfigIdList);
        } else {

            final List<String> dataConfigIdList = options.getDataConfigIdList();
            final boolean runAll = webConfigIdList == null && fileConfigIdList == null && dataConfigIdList == null;

            Thread webFsCrawlerThread = null;
            Thread dataCrawlerThread = null;

            if (runAll || webConfigIdList != null || fileConfigIdList != null) {
                webFsCrawlerThread = new Thread((Runnable) () -> {