assertThat(cache.getUnchecked(one)).isSameInstanceAs(one);
    assertThat(segment.recencyQueue.isEmpty()).isFalse();
  }

  public void testRecursiveComputation() throws InterruptedException {
    AtomicReference<LoadingCache<Integer, String>> cacheRef = new AtomicReference<>();
    CacheLoader<Integer, String> recursiveLoader =
        new CacheLoader<Integer, String>() {
          @Override
          public String load(Integer key) {

 * an {@link UnsupportedOperationException}.
 *
 * @author Charles Fry
 * @since 11.0
 */
@GwtIncompatible
public abstract class AbstractLoadingCache<K, V> extends AbstractCache<K, V>
    implements LoadingCache<K, V> {

  /** Constructor for use by subclasses. */
  protected AbstractLoadingCache() {}

  @CanIgnoreReturnValue // TODO(b/27479612): consider removing this?
  @Override
  public V getUnchecked(K key) {

 *       the cache.
 * </ul>
 *
 * <p>A lookup is specifically defined as an invocation of one of the methods {@link
 * LoadingCache#get(Object)}, {@link LoadingCache#getUnchecked(Object)}, {@link Cache#get(Object,
 * Callable)}, or {@link LoadingCache#getAll(Iterable)}.
 *
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible
public final class CacheStats {
  private final long hitCount;

 *       the cache.
 * </ul>
 *
 * <p>A lookup is specifically defined as an invocation of one of the methods {@link
 * LoadingCache#get(Object)}, {@link LoadingCache#getUnchecked(Object)}, {@link Cache#get(Object,
 * Callable)}, or {@link LoadingCache#getAll(Iterable)}.
 *
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible
public final class CacheStats {
  private final long hitCount;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.MoreObjects;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.collect.HashMultimap;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterators;

 * Cache}</a>, <a
 * href="https://www.javadoc.io/doc/com.github.ben-manes.caffeine/caffeine/latest/com.github.benmanes.caffeine/com/github/benmanes/caffeine/cache/LoadingCache.html">{@code
 * LoadingCache}</a>, <a
 * href="https://www.javadoc.io/doc/com.github.ben-manes.caffeine/caffeine/latest/com.github.benmanes.caffeine/com/github/benmanes/caffeine/cache/CacheLoader.html">{@code

  @Test
  public void loadingCache() throws ExecutionException {
    CacheLoader<Integer, Integer> loader =
        new CacheLoader<Integer, Integer>() {
          int i = 0;

          @Override
          public Integer load(Integer key) throws Exception {
            return i++;
          }
        };

    LoadingCache<Integer, Integer> cache = CacheBuilder.newBuilder().build(loader);

  @Test
  public void loadingCache() throws ExecutionException {
    CacheLoader<Integer, Integer> loader =
        new CacheLoader<Integer, Integer>() {
          int i = 0;

          @Override
          public Integer load(Integer key) throws Exception {
            return i++;
          }
        };

    LoadingCache<Integer, Integer> cache = CacheBuilder.newBuilder().build(loader);

import org.codelibs.fess.util.ComponentUtil;
import org.dbflute.optional.OptionalThing;

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;

import jakarta.annotation.PostConstruct;
import jakarta.annotation.PreDestroy;

/**
 * Helper class for managing crawler statistics and performance metrics.

import org.lastaflute.web.util.LaServletContextUtil;
import org.opensearch.common.joda.Joda;

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;

import jakarta.servlet.http.HttpServletRequest;

/**
 * Utility class providing static functions for Fess JSP/JSTL expressions and tag libraries.