*
 * @author James Sexton
 */
final class MapRetrievalCache<K, V> extends MapIteratorCache<K, V> {
  // See the note about volatile in the superclass.
  private transient volatile @Nullable CacheEntry<K, V> cacheEntry1;
  private transient volatile @Nullable CacheEntry<K, V> cacheEntry2;

  MapRetrievalCache(Map<K, V> backingMap) {
    super(backingMap);
  }

          {new MapIteratorCache<String, String>(new HashMap<String, String>())},
          {new MapIteratorCache<String, String>(new TreeMap<String, String>(nullsLast))},
          {new MapRetrievalCache<String, String>(new HashMap<String, String>())},
          {new MapRetrievalCache<String, String>(new TreeMap<String, String>(nullsLast))}
        });
  }

  @Before
  public void init() {
    mapCache.clear();
  }

  @Test

                    Set<Integer> unused = network.successors(node);
                  }
                  /*
                   * Also look up an earlier node so that, if the graph is using MapRetrievalCache,
                   * we read one of the fields declared in that class.
                   */
                  Set<Integer> unused = network.successors(first);
                  return null;
                }