* under j2objc -- but it is not detected by our j2objc cycle test. The cycle:
       *
       * - CustomScheduler.service contains an instance of ServiceDelegate. (It needs it so that it
       *   can call notifyFailed.)
       *
       * - ServiceDelegate.runningTask contains an instance of ReschedulableCallable (at least in
       *   the case that the service is using CustomScheduler). (It needs it so that it can cancel

  public <S extends Comparable<?>> Ordering<S> reverse() {
    return (Ordering<S>) ReverseNaturalOrdering.INSTANCE;
  }

  // preserving singleton-ness gives equals()/hashCode() for free
  private Object readResolve() {
    return INSTANCE;
  }

  @Override
  public String toString() {
    return "Ordering.natural()";
  }

  private NaturalOrdering() {}

    @SuppressWarnings("unchecked")
    /**
     * Creates a validator instance for form validation.
     * This method uses the system helper to create a validator with Fess-specific messages.
     *
     * @return a new action validator instance
     */
    @Override
    public ActionValidator<FessMessages> createValidator() {

   * future is {@linkplain Future#isDone() done}.
   *
   * <p>Prefer to create {@code ListenableFuture} instances with {@link SettableFuture}, {@link
   * MoreExecutors#listeningDecorator( java.util.concurrent.ExecutorService)}, {@link
   * ListenableFutureTask}, {@link AbstractFuture}, and other utilities over creating plain {@code
   * Future} instances to be upgraded to {@code ListenableFuture} after the fact.
   */

   */
  public static Function<Object, String> toStringFunction() {
    return ToStringFunction.INSTANCE;
  }

  // enum singleton pattern
  private enum ToStringFunction implements Function<Object, String> {
    INSTANCE;

    @Override
    public String apply(Object o) {
      checkNotNull(o); // eager for GWT.
      return o.toString();
    }

    @Override

    protected DocumentBuilderFactoryUtil() {
    }

    /**
     * Returns a new instance of {@link DocumentBuilderFactory}.
     *
     * @return A new instance of {@link DocumentBuilderFactory}.
     */
    public static DocumentBuilderFactory newInstance() {
        return newInstance(false);
    }

    /**
     * Returns a new instance of {@link DocumentBuilderFactory}.
     *
     * @param external

   * is the order of the first appearance of each key in this iterable.
   *
   * <p>When there are multiple instances of a key in this iterable, it is unspecified whether
   * {@code valueFunction} will be applied to more than one instance of that key and, if it is,
   * which result will be mapped to that key in the returned map.
   *

   * is the order of the first appearance of each key in this iterable.
   *
   * <p>When there are multiple instances of a key in this iterable, it is unspecified whether
   * {@code valueFunction} will be applied to more than one instance of that key and, if it is,
   * which result will be mapped to that key in the returned map.
   *

import org.apache.maven.api.Service;
import org.apache.maven.api.annotations.Nonnull;

/**
 * Registry for extensible enum values that allows looking up enum instances by their identifiers.
 * <p>
 * This service provides access to all registered instances of a specific extensible enum type.
 * It's used internally by Maven and can also be used by plugins and extensions to access

 * to prevent disk space from being consumed by old thumbnails.
 */
public class PurgeThumbnailJob {
    /** Logger instance for this class */
    private static final Logger logger = LogManager.getLogger(PurgeThumbnailJob.class);

    /**
     * Default constructor for PurgeThumbnailJob.
     * Creates a new instance of the thumbnail purging job with default expiry time (30 days).
     */
    public PurgeThumbnailJob() {