for (Vertex v : children) {
            DfsState state = stateMap.putIfAbsent(v, DfsState.VISITING);
            if (state == null) {
                cycle.addLast(v.label);
                List<String> ret = visitCycle(v.children, stateMap, cycle);
                if (ret != null) {
                    return ret;
                }
                cycle.removeLast();
                stateMap.put(v, DfsState.VISITED);

     *
     * @param key       The key associated with the extractor. Must not be null or blank.
     * @param extractor The extractor to add. Must not be null.
     */
    public void addExtractor(final String key, final Extractor extractor) {
        if (StringUtil.isBlank(key)) {
            throw new CrawlerSystemException("Extractor key (MIME type) is null or blank. Cannot register extractor without a valid key.");
        }

    var exception: String? = null
    if (wildcardMatch != null) {
      for (labelIndex in 0 until domainLabelsUtf8Bytes.size - 1) {
        val rule =
          publicSuffixList.exceptionBytes.binarySearch(
            domainLabelsUtf8Bytes,
            labelIndex,
          )
        if (rule != null) {
          exception = rule
          break
        }
      }

   */
  @Nullable V getLiveValue(ReferenceEntry<K, V> entry, long now) {
    if (entry.getKey() == null) {
      return null;
    }
    V value = entry.getValueReference().get();
    if (value == null) {
      return null;
    }

    if (isExpired(entry, now)) {
      return null;
    }
    return value;
  }

  // expiration

        addSystemProperty(cmdList, Constants.FESS_VAR_PATH, null, null);
        addSystemProperty(cmdList, Constants.FESS_THUMBNAIL_PATH, null, null);
        addSystemProperty(cmdList, "fess.log.name", getLogName("fess"), getLogName(StringUtil.EMPTY));
        if (logLevel != null) {
            cmdList.add("-Dfess.log.level=" + logLevel);
        }
        stream(fessConfig.getJvmThumbnailOptionsAsArray())

                resp.flushBuffer();
                return null;
            }
            req.getSession().setAttribute("NtlmHttpAuth", ntlm);
        } else if (!skipAuthentication) {
            final HttpSession ssn = req.getSession(false);
            if (ssn == null || (ntlm = (NtlmPasswordAuthentication) ssn.getAttribute("NtlmHttpAuth")) == null) {
                resp.setHeader("WWW-Authenticate", "NTLM");

      }
    }

    fun setupPlatform() {
      if (requiredPlatformName != null) {
        assumeTrue(getPlatformSystemProperty() == requiredPlatformName)
      }

      if (platform != null) {
        Platform.resetForTests(platform)
      } else {
        Platform.resetForTests()
      }

      if (requiredPlatformName != null) {
        System.err.println("Running with ${Platform.get().javaClass.simpleName}")

      when (val protocol = sslSocket.applicationProtocol) {
        null, "" -> null
        else -> protocol
      }
    } catch (e: UnsupportedOperationException) {
      // https://docs.oracle.com/javase/9/docs/api/javax/net/ssl/SSLSocket.html#getApplicationProtocol--
      null
    }

  override fun trustManager(sslSocketFactory: SSLSocketFactory): X509TrustManager? {

     */
    private synchronized void initLifecycleMap() {
        if (lifecycleMap == null) {
            lifecycleMap = new HashMap<>();

            if (lifecycles != null) {
                for (Lifecycle lifecycle : lifecycles) {
                    lifecycleMap.put(lifecycle.getId(), lifecycle);
                }
            } else {

     *
     * @param request The repository request from which this cache was retrieved, must not be {@code null}.
     * @param key The key to use associate the data with, must not be {@code null}.
     * @param data The data to store in the cache, may be {@code null}.
     */
    void put(RepositoryRequest request, Object key, Object data);

    /**