*
     * @param msg the error message to add; ignored if null or blank
     */
    public static void addError(final String msg) {
        if (StringUtil.isNotBlank(msg)) {
            errors.offer(msg);
        }
    }

    /**
     * Command-line options container for the crawler application.
     * This class uses args4j annotations to define command-line arguments

                final String thumbnailField = fessConfig.getIndexFieldThumbnail();
                docList.stream().forEach(doc -> {
                    if (!thumbnailManager.offer(doc)) {
                        if (logger.isDebugEnabled()) {
                            logger.debug("Removing {}={} from doc[{}]", thumbnailField, doc.get(thumbnailField),

 *       actually do so, to avoid implying repeat-iterability.) {@code FluentIterable}, on the other
 *       hand, is multiple-use, and does implement {@link Iterable}.
 *   <li>Streams offer many features not found here, including {@code min/max}, {@code distinct},
 *       {@code reduce}, {@code sorted}, the very powerful {@code collect}, and built-in support for
 *       parallelizing stream operations.

 *       actually do so, to avoid implying repeat-iterability.) {@code FluentIterable}, on the other
 *       hand, is multiple-use, and does implement {@link Iterable}.
 *   <li>Streams offer many features not found here, including {@code min/max}, {@code distinct},
 *       {@code reduce}, {@code sorted}, the very powerful {@code collect}, and built-in support for
 *       parallelizing stream operations.

_2020-03-17_

**This release candidate turns on web socket compression.**

The [spec][rfc_7692] includes a sophisticated mechanism for client and server to negotiate
compression features. We strive to offer great performance in our default configuration and so we're
making compression the default for everyone starting with this release candidate.

    private final long batchTimeout = 100;  // 100ms
    
    public void addNotification(WitnessNotification notification) {
        synchronized (pendingNotifications) {
            pendingNotifications.offer(notification);
            
            if (pendingNotifications.size() >= batchSize) {
                processBatch();
            }
        }
    }
    
    private void processBatch() {

 *  Fix: Don't send both `If-None-Match` and `If-Modified-Since` cache headers
    when both are applicable.
 *  Fix: Fail early when a port is out of range.
 *  Fix: Offer `Content-Length` headers for multipart request bodies.
 *  Fix: Throw `UnknownServiceException` if a cleartext connection is attempted
    when explicitly forbidden.

 * `Function<@Nullable A, @Nullable B>` already had to find a workaround. Still, there is a *ton* of
 * fallout from trying to switch. I would be shocked if the switch would offer benefits to anywhere
 * near enough users to justify the costs.
 *
 * Fortunately, if anyone does want to use a Converter as a `Function<@Nullable A, @Nullable B>`,
 * it's easy to get one: `converter::convert`.
 *

			x.versions = append(x.versions[:i], x.versions[i+1:]...)
			// if uv has tiered content we add a
			// free-version to track it for
			// asynchronous deletion via scanner.
			if freeVersion, toFree := ver.ObjectV2.InitFreeVersion(fi); toFree {
				err = x.addVersion(freeVersion)
			}
		}

		if fi.Deleted {
			err = x.addVersion(ventry)
		}

    val latch = CountDownLatch(1)
    val responses: BlockingQueue<String?> = SynchronousQueue()
    val authenticator =
      okhttp3.Authenticator { route: Route?, response: Response? ->
        responses.offer(response!!.body.string())
        try {
          latch.await()
        } catch (e: InterruptedException) {
          throw AssertionError()
        }
        response.request
      }