public void setLabelTypeIds(final String[] labelTypeIds) {
        this.labelTypeIds = labelTypeIds;
    }

    public List<LabelType> getLabelTypeList() {
        if (labelTypeList == null) {
            synchronized (this) {
                if (labelTypeList == null) {
                    final FessConfig fessConfig = ComponentUtil.getFessConfig();

  static class Key {
    private final int value;
    private WeakReference<String> toString;

    Key(int value) {
      this.value = value;
    }

    @Override
    public synchronized String toString() {
      String s;
      if (toString != null) {
        s = toString.get();
        if (s != null) {
          return s;
        }
      }
      s = Integer.toString(value);

    }
    enumConstantCache.put(enumClass, result);
    return result;
  }

  static <T extends Enum<T>> Map<String, WeakReference<? extends Enum<?>>> getEnumConstants(
      Class<T> enumClass) {
    synchronized (enumConstantCache) {
      Map<String, WeakReference<? extends Enum<?>>> constants = enumConstantCache.get(enumClass);
      if (constants == null) {
        constants = populateCache(enumClass);
      }

    /**
     * Returns a {@link Logger}.
     *
     * @param clazz
     *            Class to be used as the logger category. Must not be {@literal null}.
     * @return {@link Logger}
     */
    public static synchronized Logger getLogger(final Class<?> clazz) {
        assertArgumentNotNull("clazz", clazz);

        if (!initialized) {
            initialize();
        }
        Logger logger = loggers.get(clazz);

        writeUtf8("\r\n")
        write(source, byteCount)
        writeUtf8("\r\n")
      }
    }

    @Synchronized
    override fun flush() {
      if (closed) return // Don't throw; this stream might have been closed on the caller's behalf.
      socket.sink.flush()
    }

    @Synchronized
    override fun close() {
      if (closed) return
      closed = true
      socket.sink.writeUtf8("0\r\n\r\n")

        val totalExceptionBytes = bufferedSource.readInt()
        publicSuffixExceptionListBytes = bufferedSource.readByteString(totalExceptionBytes.toLong())
      }

      synchronized(this) {
        this.bytes = publicSuffixListBytes!!
        this.exceptionBytes = publicSuffixExceptionListBytes!!
      }
    } finally {
      readCompleteLatch.countDown()
    }
  }

/**
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */
@Deprecated(since = "4.0.0")
class Graph {

    final Map<String, Set<String>> graph = new LinkedHashMap<>();

    synchronized void addEdge(String from, String to) throws CycleDetectedException {
        if (graph.computeIfAbsent(from, l -> new HashSet<>()).add(to)) {

 *   // do other things since the monitor was not available
 * }
 * }
 *
 * <h2>Comparison with {@code synchronized} and {@code ReentrantLock}</h2>
 *
 * <p>The following examples show a simple threadsafe holder expressed using {@code synchronized},
 * {@link ReentrantLock}, and {@code Monitor}.
 *
 * <h3>{@code synchronized}</h3>
 *
 * <p>This version is the fewest lines of code, largely because the synchronization mechanism used

    abstract val fileSystemOperations: FileSystemOperations

    private
    var hasCleaned = false

    val logger = Logging.getLogger(CachesCleaner::class.java)

    fun cleanUpCaches() {
        synchronized(this) {
            if (hasCleaned) {
                return
            }
            logger.lifecycle("Cleaning up caches...")
            val homeDir = parameters.homeDir.get()

                            boolean contains = pool.contains(null); // Should handle gracefully
                            successCount.incrementAndGet();
                        } catch (Exception e) {
                            synchronized (exceptions) {
                                exceptions.add(e);
                            }
                        }
                    }
                    long threadEnd = System.nanoTime();