}

    default void setDefaultLabelValue(final String value) {
        setSystemProperty(Constants.DEFAULT_LABEL_VALUE_PROPERTY, value);
        propMap.remove(DEFAULT_LABEL_VALUES);
    }

    default String getDefaultLabelValue() {
        return getSystemProperty(Constants.DEFAULT_LABEL_VALUE_PROPERTY, StringUtil.EMPTY);
    }

   *     // operate on tuple
   *   }
   * }
   * }
   *
   * <p>Note that if any input set is empty, the Cartesian product will also be empty. If no sets at
   * all are provided (an empty list), the resulting Cartesian product has one element, an empty
   * list (counter-intuitive, but mathematically consistent).
   *

 *
 * If a path's last segment is the empty string then the path ends with "/". This class always
 * builds non-empty paths: if the path is omitted it defaults to "/". The default path's segment
 * list is a single empty string: `[""]`.
 *
 * ### Query
 *
 * The query is optional: it can be null, empty, or non-empty. For many HTTP URLs the query string

@GwtCompatible
public final class Iterators {
  private Iterators() {}

  /**
   * Returns the empty iterator.
   *
   * <p>The {@link Iterable} equivalent of this method is {@link ImmutableSet#of()}.
   */
  static <T extends @Nullable Object> UnmodifiableIterator<T> emptyIterator() {
    return emptyListIterator();
  }

  /**
   * Returns the empty iterator.
   *

     *
     * @param map the map
     * @return {@literal true} if the map is {@literal null} or empty
     */
    public static boolean isEmpty(final Map<?, ?> map) {
        return map == null || map.isEmpty();
    }

    /**
     * Returns {@literal true} if the given {@link Map} is not {@literal null} and not empty.
     *
     * @param map the map

                } catch (final IOException e) {
                    throw new IORuntimeException(e);
                }
                return true;
            }, OptionalThing.empty());
            response.flushBuffer();
            if (logger.isDebugEnabled()) {
                logger.debug("Loaded {} docs", count);
            }

     * @return the string with highlight tags removed
     */
    protected String removeHighlightTag(final String str) {
        return str.replaceAll(originalHighlightTagPre, StringUtil.EMPTY).replaceAll(originalHighlightTagPost, StringUtil.EMPTY);
    }

    /**
     * Creates highlight information based on screen width.
     * Adjusts fragment size for mobile devices.
     *
     * @return the highlight information

     * @return an optional containing the authenticated user if successful, empty otherwise
     */
    public OptionalEntity<FessUser> login(final String username, final String password) {
        if (StringUtil.isBlank(fessConfig.getLdapProviderUrl()) || !validate()) {
            return OptionalEntity.empty();
        }

        final Hashtable<String, String> env = createSearchEnv(username, password);

   * provided, and they should not use soft, weak, or phantom references.
   *
   * @param map place to store the mapping from each key to its corresponding values
   * @param factory supplier of new, empty lists that will each hold all values for a given key
   * @throws IllegalArgumentException if {@code map} is not empty
   */

   * provided, and they should not use soft, weak, or phantom references.
   *
   * @param map place to store the mapping from each key to its corresponding values
   * @param factory supplier of new, empty lists that will each hold all values for a given key
   * @throws IllegalArgumentException if {@code map} is not empty
   */