* expireAfterWrite}, {@link #expireAfterAccess expireAfterAccess}, {@link #weakKeys weakKeys},
 * {@link #weakValues weakValues}, or {@link #softValues softValues} are requested.
 *
 * <p>If {@link #maximumSize(long) maximumSize} or {@link #maximumWeight(long) maximumWeight} is
 * requested entries may be evicted on each cache modification.
 *

    CountingLoader countingLoader = new CountingLoader();
    LoadingCache<Object, Object> cache =
        CacheBuilder.newBuilder().weakValues().build(countingLoader);
    ConcurrentMap<Object, Object> map = cache.asMap();

    int iterations = 10;
    WeakReference<Object> ref = new WeakReference<>(null);
    int expectedComputations = 0;