// TODO(fry): could also cancel loading if we had a handle on its future
    }

    public ListenableFuture<V> loadFuture(K key, CacheLoader<? super K, V> loader) {
      try {
        stopwatch.start();
        V previousValue = oldValue.get();
        if (previousValue == null) {
          V newValue = loader.load(key);
          return set(newValue) ? futureValue : Futures.immediateFuture(newValue);
        }