TearDownStack result = new TearDownStack();
    tearDownStack.addTearDown(
        new TearDown() {

          @Override
          public void tearDown() throws Exception {
            synchronized (result.lock) {
              assertEquals(
                  "The test should have cleared the stack (say, by virtue of running runTearDown)",
                  0,
                  result.stack.size());

    protected abstract FileEntry[] getResults();

    /**
     * Closes the enumeration and releases resources.
     *
     * @throws CIFSException if an error occurs during closing
     */
    protected synchronized void doClose() throws CIFSException {
        // otherwise already closed
        if (!this.closed) {
            this.closed = true;
            try {
                doCloseInternal();
            } finally {

 *   // 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

  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);

                synchronized (result) {
                    result.addMissingArtifact(artifact);
                }
            } catch (ArtifactResolutionException e) {
                // This is really a wagon TransferFailedException so something went wrong after we successfully
                // retrieved the metadata.

                synchronized (result) {

     */
    @Override
    public void refresh() throws CIFSException {
        log.debug("Refreshing JAAS credentials");
        this.cachedSubject = null;
    }

    @Override
    public synchronized Subject getSubject() {
        if (this.cachedSubject != null) {
            return this.cachedSubject;
        }

        try {
            log.debug("Logging on");
            LoginContext lc;

    assertTrue(Thread.holdsLock(mutex));
    return super.isEmpty();
  }

  /*
   * We don't assert that the lock is held during calls to iterator(), stream(), and spliterator:
   * `Synchronized` doesn't guarantee that it will hold the mutex for those calls because callers
   * are responsible for taking the mutex themselves:

        }
        buffer.setLength(buffer.length() - ", ".length());
        return new String(buffer);
    }

    /**
     * Initializes the class.
     */
    protected static synchronized void initialize() {
        if (!initialized) {
            DisposableUtil.add(() -> {
                ResourceBundle.clearCache();
                initialized = false;
            });

        }
    }

    public void test_evaluate_concurrency() {
        queryRescorer = new QueryRescorer() {
            private int callCount = 0;

            @Override
            public synchronized RescorerBuilder<?> evaluate(Map<String, Object> params) {
                callCount++;
                if (callCount % 2 == 0) {
                    return createMockRescorerBuilder();
                }

                this.uhe = uhe;
            } catch (final Exception ex) {
                this.uhe = new UnknownHostException(ex.getMessage());
            } finally {
                synchronized (sem) {
                    sem.count--;
                    sem.notify();
                }
            }
        }
    }