* This prevents stack trace generation for this exception type.
     *
     * @return null to skip stack trace generation
     */
    @Override
    public synchronized Throwable fillInStackTrace() {
        return null;
    }

import java.io.OutputStream;

class SocketOutputStream extends FilterOutputStream {

    SocketOutputStream(final OutputStream out) {
        super(out);
    }

    @Override
    public synchronized void write(final byte[] b, int off, final int len) throws IOException {
        if (len > 0xFFFF) {
            throw new IOException("write too large: " + len);
        }
        if (off < 4) {

         * This method creates a GCS Storage client using environment variables for configuration.
         * This method is synchronized to ensure thread-safe connection initialization.
         *
         * @throws IOException If the connection cannot be established
         */
        @Override
        public synchronized void connect() throws IOException {
            if (connected) {
                return;
            }

         * This method creates an AWS S3 client using environment variables for configuration.
         * This method is synchronized to ensure thread-safe connection initialization.
         *
         * @throws IOException If the connection cannot be established
         */
        @Override
        public synchronized void connect() throws IOException {
            if (connected) {
                return;
            }

    /**
     * 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);

     * @param path the path to resolve
     * @param auth the authentication credentials
     * @return a DFS referral for the resolved path
     * @throws SmbAuthException if authentication fails
     */
    public synchronized DfsReferral resolve(String domain, String root, final String path, final NtlmPasswordAuthentication auth)
            throws SmbAuthException {
        DfsReferral dr = null;
        final long now = System.currentTimeMillis();

         * This method creates a MinIO client using environment variables for configuration.
         * This method is synchronized to ensure thread-safe connection initialization.
         *
         * @throws IOException If the connection cannot be established
         */
        @Override
        public synchronized void connect() throws IOException {
            if (connected) {
                return;
            }

    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();

                            TestComponent component = factory.create();
                            synchronized (createdComponents) {
                                createdComponents.add(component);
                            }
                        }
                    } catch (Exception e) {
                        synchronized (exceptions) {
                            exceptions.add(e);
                        }

  }

  private static class TestApplication extends Application {
    private final List<Thread> hooks = new ArrayList<>();

    @Override
    synchronized void addShutdownHook(Thread hook) {
      hooks.add(hook);
    }

    synchronized void shutdown() throws InterruptedException {
      for (Thread hook : hooks) {
        hook.start();
      }
      for (Thread hook : hooks) {
        hook.join();