}

    }

    /**
     * Checks if a URL is new.
     *
     * @param urlQueue The URL queue.
     * @param urlQueueList The list of URL queues.
     * @return true if the URL is new, otherwise false.
     */
    protected boolean isNewUrl(final UrlQueueImpl<Long> urlQueue, final Queue<UrlQueueImpl<Long>> urlQueueList) {

        final String url = urlQueue.getUrl();
        if (StringUtil.isBlank(url)) {

    assertEquals(3, uniqueEntries.size());
  }

  // Wrapper of EnumMultiset factory methods, because we need to skip create(Class).
  // create(Enum1.class) is equal to create(Enum2.class) but testEquals() expects otherwise.
  // For the same reason, we need to skip create(Iterable, Class).
  private static class EnumMultisetFactory {
    @Keep // used reflectively by testEquals

## Concepts

- If an object is under legal hold, it cannot be deleted unless the legal hold is explicitly removed for the respective version id. DeleteObjectVersion() would fail otherwise.
- In `Compliance` mode, objects cannot be deleted by anyone until retention period has expired for the given version id. If user has governance bypass permissions, an object's retention date can be extended in `Compliance` mode.

   *
   * @param string the string to test and possibly return
   * @return {@code string} itself if it is non-null; {@code ""} if it is null
   */
  public static String nullToEmpty(@Nullable String string) {
    return Platform.nullToEmpty(string);
  }

  /**
   * Returns the given string if it is nonempty; {@code null} otherwise.
   *

   * Returns a resolver that resolves types "invariantly".
   *
   * <p>For example, when resolving {@code List<T>} in the context of {@code ArrayList<?>}, {@code
   * <T>} cannot be invariantly resolved to {@code <?>} because otherwise the parameter type of
   * {@code List::set} will be {@code <?>} and it'll falsely say any object can be passed into
   * {@code ArrayList<?>::set}.
   *

   * Returns an array containing all of the elements in this queue, in proper sequence; the runtime
   * type of the returned array is that of the specified array. If the queue fits in the specified
   * array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the
   * specified array and the size of this queue.
   *
   * <p>If this queue fits in the specified array with room to spare (i.e., the array has more

            if (log.isDebugEnabled()) {
                log.debug(String.format("Retrying (%d/%d) request %s", retries, maxRetries, request));
            }

            // should we disconnect the transport here? otherwise we make an additional attempt to detect that if the
            // server closed the connection as a result
            log.debug("Disconnecting tree on send retry", last);
            disconnect(true);

     * the given URL. If the URL matches the exclusion pattern, the method returns {@code false},
     * indicating that the URL should not be crawled. Otherwise, it returns {@code true}.
     *
     * @param paramMap the parameter map containing potential exclusion patterns
     * @param url the URL to be checked for crawlability

     * @param id the document ID to update
     * @param field the field name to update
     * @param value the new value for the field
     * @return true if the update was successful, false otherwise
     */
    public boolean updateDocument(final SearchEngineClient searchEngineClient, final String id, final String field, final Object value) {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();

                sums.put(extension, observer.getActualChecksum());
            }

            // We do this in here so we can checksum the artifact metadata too, otherwise it could be metadata itself
            for (String extension : checksums.keySet()) {
                // TODO shouldn't need a file intermediary - improve wagon to take a stream