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);
      }

     */
    private final int priority;

    /**
     * Parses the phase identifier.
     *
     * @param phase the phase identifier.
     * @return the {@link PhaseId}.
     */
    public static synchronized PhaseId of(String phase) {
        return INSTANCES.computeIfAbsent(phase, PhaseId::new);
    }

    /**
     * Constructor.
     *
     * @param phase the phase identifier string.
     */

    /**
     * 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);

    }

    /**
     * Plexus: Populates the lifecycle map from the injected list of lifecycle mappings (if not already done).
     */
    private synchronized void initLifecycleMap() {
        if (lifecycleMap == null) {
            lifecycleMap = new HashMap<>();

            if (lifecycles != null) {
                for (Lifecycle lifecycle : lifecycles) {

        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)) {

  private TearDownStack buildTearDownStack() {
    TearDownStack result = new TearDownStack();
    tearDownStack.addTearDown(
        () -> {
          synchronized (result.lock) {
            assertEquals(
                "The test should have cleared the stack (say, by virtue of running runTearDown)",
                0,
                result.stack.size());
          }

        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")

 * {@link Map} specified in the {@link Table} interface.
 *
 * <p>Note that this implementation is not synchronized. If multiple threads access this table
 * concurrently and one of the threads modifies the table, it must be synchronized externally.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#table">{@code Table}</a>.
 *