* @param <V> the type of the cache's values, which are not permitted to be null
 * @author Charles Fry
 * @since 11.0
 */
@GwtCompatible
public interface LoadingCache<K, V> extends Cache<K, V>, Function<K, V> {

  /**
   * Returns the value associated with {@code key} in this cache, first loading that value if

  private Iterable<LoadingCache<Object, Object>> caches() {
    // lots of different ways to configure a LoadingCache
    CacheBuilderFactory factory = cacheFactory();
    return Iterables.transform(
        factory.buildAllPermutations(),
        new Function<CacheBuilder<Object, Object>, LoadingCache<Object, Object>>() {
          @Override

import com.google.common.util.concurrent.UncheckedExecutionException;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * {@link LoadingCache} tests for caches with a maximum size of zero.
 *
 * @author mike nonemacher
 */
@NullUnmarked
public class NullCacheTest extends TestCase {
  QueuingRemovalListener<Object, Object> listener;

  @Override

import com.google.common.util.concurrent.UncheckedExecutionException;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * {@link LoadingCache} tests for caches with a maximum size of zero.
 *
 * @author mike nonemacher
 */
@NullUnmarked
public class NullCacheTest extends TestCase {
  QueuingRemovalListener<Object, Object> listener;

  @Override

  }

  /**
   * Make sure LoadingCache correctly wraps ExecutionExceptions and UncheckedExecutionExceptions.
   */
  public void testLoadingExceptionWithCause() {
    Exception cause = new Exception();
    UncheckedExecutionException uee = new UncheckedExecutionException(cause);
    ExecutionException ee = new ExecutionException(cause);

    LoadingCache<Object, Object> cacheUnchecked =

  }

  /**
   * Make sure LoadingCache correctly wraps ExecutionExceptions and UncheckedExecutionExceptions.
   */
  public void testLoadingExceptionWithCause() {
    Exception cause = new Exception();
    UncheckedExecutionException uee = new UncheckedExecutionException(cause);
    ExecutionException ee = new ExecutionException(cause);

    LoadingCache<Object, Object> cacheUnchecked =

  private Iterable<LoadingCache<Object, Object>> caches() {
    // lots of different ways to configure a LoadingCache
    CacheBuilderFactory factory = cacheFactory();
    return Iterables.transform(
        factory.buildAllPermutations(),
        new Function<CacheBuilder<Object, Object>, LoadingCache<Object, Object>>() {
          @Override

  private Iterable<LoadingCache<Object, Object>> caches() {
    // lots of different ways to configure a LoadingCache
    CacheBuilderFactory factory = cacheFactory();
    return Iterables.transform(
        factory.buildAllPermutations(),
        new Function<CacheBuilder<Object, Object>, LoadingCache<Object, Object>>() {
          @Override

   *
   * <p>This method should be overridden when bulk retrieval is significantly more efficient than
   * many individual lookups. Note that {@link LoadingCache#getAll} will defer to individual calls
   * to {@link LoadingCache#get} if this method is not overridden.
   *
   * @param keys the unique, non-null keys whose values should be loaded

  private Iterable<LoadingCache<Object, Object>> caches() {
    // lots of different ways to configure a LoadingCache
    CacheBuilderFactory factory = cacheFactory();
    return Iterables.transform(
        factory.buildAllPermutations(),
        new Function<CacheBuilder<Object, Object>, LoadingCache<Object, Object>>() {
          @Override