* more simply:
 *
 * {@snippet :
 * CacheLoader<Key, Graph> loader = CacheLoader.from(key -> createExpensiveGraph(key));
 * }
 *
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible
public abstract class CacheLoader<K, V> {
  /** Constructor for use by subclasses. */
  protected CacheLoader() {}

  /**
   * Computes or retrieves the value corresponding to {@code key}.
   *

   *
   * <p>Caches loaded by a {@link CacheLoader} will issue a single request to {@link
   * CacheLoader#loadAll} for all keys which are not already present in the cache. All entries
   * returned by {@link CacheLoader#loadAll} will be stored in the cache, over-writing any
   * previously cached values. This method will throw an exception if {@link CacheLoader#loadAll}

    AtomicInteger loadCount = new AtomicInteger();
    AtomicInteger reloadCount = new AtomicInteger();
    AtomicInteger loadAllCount = new AtomicInteger();

    CacheLoader<Object, Object> baseLoader =
        new CacheLoader<Object, Object>() {
          @Override
          public Object load(Object key) {
            loadCount.incrementAndGet();
            return new Object();
          }

/**
 * Utility {@link CacheLoader} implementations intended for use in testing.
 *
 * @author mike nonemacher
 */
@GwtCompatible
@NullUnmarked
final class TestingCacheLoaders {

  /**
   * Returns a {@link CacheLoader} that implements a naive {@link CacheLoader#loadAll}, delegating
   * {@link CacheLoader#load} calls to {@code loader}.
   */
  static <K, V> CacheLoader<K, V> bulkLoader(CacheLoader<K, V> loader) {

    AtomicInteger loadCount = new AtomicInteger();
    AtomicInteger reloadCount = new AtomicInteger();
    AtomicInteger loadAllCount = new AtomicInteger();

    CacheLoader<Object, Object> baseLoader =
        new CacheLoader<Object, Object>() {
          @Override
          public Object load(Object key) {
            loadCount.incrementAndGet();
            return new Object();
          }

 * strengths.
 *
 * @author mike nonemacher
 */
@NullUnmarked
public class CacheReferencesTest extends TestCase {

  private static final CacheLoader<Key, String> KEY_TO_STRING_LOADER =
      new CacheLoader<Key, String>() {
        @Override
        public String load(Key key) {
          return key.toString();
        }
      };

    cache =
        CacheBuilder.newBuilder()
            .concurrencyLevel(segments)
            .maximumSize(maximumSize)
            .build(
                new CacheLoader<Integer, Integer>() {
                  @Override
                  public Integer load(Integer from) {
                    return (int) misses.incrementAndGet();
                  }
                });

import org.opensearch.action.DocWriteRequest.OpType;
import org.opensearch.index.query.QueryBuilders;

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

import jakarta.annotation.PostConstruct;

/**
 * OpenSearchUrlFilterService is an implementation of {@link UrlFilterService} for OpenSearch.
 */

 * strengths.
 *
 * @author mike nonemacher
 */
@NullUnmarked
public class CacheReferencesTest extends TestCase {

  private static final CacheLoader<Key, String> KEY_TO_STRING_LOADER =
      new CacheLoader<Key, String>() {
        @Override
        public String load(Key key) {
          return key.toString();
        }
      };

   *   <li>consolidation of the loader logic to {@linkplain CacheBuilder#build(CacheLoader) a single
   *       authoritative location}
   *   <li>{@linkplain LoadingCache#refresh refreshing of entries}, including {@linkplain
   *       CacheBuilder#refreshAfterWrite automated refreshing}
   *   <li>{@linkplain LoadingCache#getAll bulk loading requests}, including {@linkplain
   *       CacheLoader#loadAll bulk loading implementations}
   * </ul>
   *