code: final protected Entry<K, V> peekEntryInternal(K key) {
      int hc = modifiedHash(key.hashCode());
      return peekEntryInternal(key, hc, extractIntKeyValue(key, hc));
    }
docs: Return the entry, if it is in the cache, without invoking the
  cache source.
  
  <p>The cache storage is asked whether the entry is present.
  If the entry is not present, this result is cached in the local
  cache.