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

  public static <K, V> CacheLoader<K, V> asyncReloading(
      final CacheLoader<K, V> loader, final Executor executor) {
    checkNotNull(loader);
    checkNotNull(executor);
    return new CacheLoader<K, V>() {
      @Override
      public V load(K key) throws Exception {
        return loader.load(key);
      }

      @Override
      public ListenableFuture<V> reload(final K key, final V oldValue) {

    }
  }

  /**
   * On a concurrent computation that returns null, all threads should get an
   * InvalidCacheLoadException, with the loader only called once. The result should not be cached (a
   * later request should call the loader again).
   */
  private static void testConcurrentLoadingNull(CacheBuilder<Object, Object> builder)
      throws InterruptedException {

    int count = 10;

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

   * {@linkplain Thread#getContextClassLoader() context class loader}. In simple environments, the
   * context class loader will find resources from the class path. In environments where different
   * threads can have different class loaders, for example app servers, the context class loader
   * will typically have been set to an appropriate loader for the current thread.
   *

    }
  }

  /**
   * On a concurrent computation that returns null, all threads should get an
   * InvalidCacheLoadException, with the loader only called once. The result should not be cached (a
   * later request should call the loader again).
   */
  private static void testConcurrentLoadingNull(CacheBuilder<Object, Object> builder)
      throws InterruptedException {

    int count = 10;

   *       CacheLoader#loadAll bulk loading implementations}
   * </ul>
   *
   * <p><b>Warning:</b> For any given key, every {@code loader} used with it should compute the same
   * value. Otherwise, a call that passes one {@code loader} may return the result of another call
   * with a differently behaving {@code loader}. For example, a call that requests a short timeout
   * for an RPC may wait for a similar call that requests a long timeout, or a call by an

  private final CacheLoader<? super K, V> loader;
  private final RemovalListener<? super K, ? super V> removalListener;
  private final StatsCounter statsCounter;
  private final Ticker ticker;
  private final long expireAfterWrite;
  private final long expireAfterAccess;

  LocalCache(CacheBuilder<? super K, ? super V> builder, CacheLoader<? super K, V> loader) {
    this.loader = loader;
    this.removalListener = builder.removalListener;

    CountingLoader loader = new CountingLoader();
    LocalCache<Object, Object> map = makeLocalCache(createCacheBuilder());
    assertEquals(0, loader.getCount());

    Object key = new Object();
    Object value = map.get(key, loader);
    assertEquals(1, loader.getCount());
    assertEquals(value, map.get(key, loader));
    assertEquals(1, loader.getCount());
  }

    CountingLoader loader = new CountingLoader();
    LocalCache<Object, Object> map = makeLocalCache(createCacheBuilder());
    assertEquals(0, loader.getCount());

    Object key = new Object();
    Object value = map.get(key, loader);
    assertEquals(1, loader.getCount());
    assertEquals(value, map.get(key, loader));
    assertEquals(1, loader.getCount());
  }