* @param <V> the type of the cache's values, which are not permitted to be null
 * @author Charles Fry
 * @since 11.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
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

 * @param <V> the type of the cache's values, which are not permitted to be null
 * @author Charles Fry
 * @since 11.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
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.cache.TestingRemovalListeners.QueuingRemovalListener;
import com.google.common.util.concurrent.UncheckedExecutionException;
import junit.framework.TestCase;

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

  @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

/** Unit tests for CacheBuilder. */
@GwtCompatible(emulated = true)
public class CacheBuilderTest extends TestCase {

  public void testNewBuilder() {
    CacheLoader<Object, Integer> loader = constantLoader(1);

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

    assertEquals(Integer.valueOf(1), cache.getUnchecked("one"));
    assertEquals(1, cache.size());
  }

  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

    LoadingCache<String, Integer> cache =
        CacheBuilder.newBuilder()
            .expireAfterAccess(EXPIRING_TIME, MILLISECONDS)
            .removalListener(removalListener)
            .ticker(ticker)
            .build(loader);
    checkExpiration(cache, loader, ticker, removalListener);
  }

  private void checkExpiration(
      LoadingCache<String, Integer> cache,

  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

  }

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

    LoadingCache<Object, Object> cacheUnchecked =