}

  private Iterable<LoadingCache<Key, String>> caches() {
    CacheBuilderFactory factory = factoryWithAllKeyStrengths();
    return Iterables.transform(
        factory.buildAllPermutations(),
        new Function<CacheBuilder<Object, Object>, LoadingCache<Key, String>>() {
          @Override
          public LoadingCache<Key, String> apply(CacheBuilder<Object, Object> builder) {

  CacheBuilderFactory withValueStrengths(Set<Strength> valueStrengths) {
    this.valueStrengths = new LinkedHashSet<>(valueStrengths);
    return this;
  }

  Iterable<CacheBuilder<Object, Object>> buildAllPermutations() {
    Iterable<List<Object>> combinations =
        buildCartesianProduct(
            concurrencyLevels,
            initialCapacities,
            maximumSizes,
            expireAfterWrites,