final HttpCacheEntry updatedValue = HttpTestUtils.makeCacheEntry();
final byte[] oldBytes = HttpTestUtils.getRandomBytes(128);
final CASValue<Object> casValue = new CASValue<Object>(1, oldBytes);
final byte[] newBytes = HttpTestUtils.getRandomBytes(128);
final CacheConfig config = CacheConfig.custom().setMaxUpdateRetries(0).build();
impl = new MemcachedHttpCacheStorage(mockMemcachedClient, config,
mockMemcachedCacheEntryFactory, mockKeyHashingScheme);
final HttpCacheUpdateCallback callback = new HttpCacheUpdateCallback() {
public HttpCacheEntry update(final HttpCacheEntry old) {