* An {@code Integer} loader that returns the key for {@code load} requests, and increments the
   * old value on {@code reload} requests. The load counts are accessible via {@link #getLoadCount}
   * and {@link #getReloadCount}.
   */
  static class IncrementingLoader extends CacheLoader<Integer, Integer> {
    private final AtomicInteger countLoad = new AtomicInteger();
    private final AtomicInteger countReload = new AtomicInteger();