dataCrawlingThread.setPriority(crawlerPriority);
            dataCrawlingThread.setName(sid);
            dataCrawlingThread.setDaemon(true);

            dataCrawlingThreadList.add(dataCrawlingThread);
            dataCrawlingThreadStatusList.add(Constants.READY);

        }

        int startedCrawlerNum = 0;

        public Thread newThread(Runnable r) {
            Thread newThread = new Thread(GROUP, r, "resolver-" + THREAD_NUMBER.getAndIncrement());
            newThread.setDaemon(true);
            newThread.setContextClassLoader(null);
            return newThread;
        }
    }

    private class ResolveTask implements Runnable {

        private final ClassLoader classLoader;

        indexUpdater.setName("IndexUpdater");
        indexUpdater.setPriority(indexUpdaterPriority);
        indexUpdater.setSessionIdList(sessionIdList);
        indexUpdater.setDaemon(true);
        indexUpdater.setCrawlerList(crawlerList);
        getAvailableBoostDocumentRuleList().forEach(rule -> {
            indexUpdater.addDocBoostMatcher(new org.codelibs.fess.indexer.DocBoostMatcher(rule));

  }

  @J2ktIncompatible
  @GwtIncompatible // TODO
  private static void useDaemonThreadFactory(ThreadPoolExecutor executor) {
    executor.setThreadFactory(
        new ThreadFactoryBuilder()
            .setDaemon(true)
            .setThreadFactory(executor.getThreadFactory())
            .build());
  }

  // See newDirectExecutorService javadoc for behavioral notes.
  @J2ktIncompatible
  @GwtIncompatible // TODO

  }

  /** Returns a new started daemon Thread running the given runnable. */
  Thread newStartedThread(Runnable runnable) {
    Thread t = new Thread(runnable);
    t.setDaemon(true);
    t.start();
    return t;
  }

  /**
   * Waits for the specified time (in milliseconds) for the thread to terminate (using {@link

  }

  /** Returns a new started daemon Thread running the given runnable. */
  Thread newStartedThread(Runnable runnable) {
    Thread t = new Thread(runnable);
    t.setDaemon(true);
    t.start();
    return t;
  }

  /**
   * Waits for the specified time (in milliseconds) for the thread to terminate (using {@link