static final Object NULL = new Object();

  static final LazyLogger log = new LazyLogger(AbstractFuture.class);

  static final boolean GENERATE_CANCELLATION_CAUSES = false;

  private volatile @Nullable Object value;

  private volatile @Nullable Listener listeners;

      implements Supplier<T>, Serializable {
    private transient Object lock = new Object();

    final Supplier<T> delegate;
    transient volatile boolean initialized;
    // "value" does not need to be volatile; visibility piggy-backs
    // on volatile read of "initialized".
    transient @Nullable T value;

    MemoizingSupplier(Supplier<T> delegate) {
      this.delegate = checkNotNull(delegate);
    }

      implements Supplier<T>, Serializable {
    private transient Object lock = new Object();

    final Supplier<T> delegate;
    transient volatile boolean initialized;
    // "value" does not need to be volatile; visibility piggy-backs
    // on volatile read of "initialized".
    transient @Nullable T value;

    MemoizingSupplier(Supplier<T> delegate) {
      this.delegate = checkNotNull(delegate);
    }

   *
   * Note about volatile: volatile doesn't make it safe to read from a mutable graph in one thread
   * while writing to it in another. All it does is help with _reading_ from multiple threads
   * concurrently. For more information, see AbstractNetworkTest.concurrentIteration.
   */
  private transient volatile @Nullable Entry<K, V> cacheEntry;

  MapIteratorCache(Map<K, V> backingMap) {

   *       argument.
   * </ul>
   */
  volatile @Nullable Object valueField;

  /** All listeners. */
  volatile @Nullable Listener listenersField;

  /** All waiting threads. */
  volatile @Nullable Waiter waitersField;

  /** Non-volatile write of the thread to the {@link Waiter#thread} field. */

   *       argument.
   * </ul>
   */
  volatile @Nullable Object valueField;

  /** All listeners. */
  volatile @Nullable Listener listenersField;

  /** All waiting threads. */
  volatile @Nullable Waiter waitersField;

  /** Non-volatile write of the thread to the {@link Waiter#thread} field. */

     *
     * As a guide, all critical volatile reads and writes to the count field are marked in code
     * comments.
     */

    @Weak final MapMakerInternalMap<K, V, E, S> map;

    /**
     * The number of live elements in this segment's region. This does not include unset elements
     * which are awaiting cleanup.
     */
    volatile int count;

    /**

   *
   * <p>JVM intrinsics note: It would be possible to use a release-only form of CAS here, if it were
   * provided.
   */
  static final class Cell {
    volatile long p0, p1, p2, p3, p4, p5, p6;
    volatile long value;
    volatile long q0, q1, q2, q3, q4, q5, q6;

    Cell(long x) {
      value = x;
    }

    final boolean cas(long cmp, long val) {

 */
public class WebConfig extends BsWebConfig implements CrawlingConfig {

    private static final long serialVersionUID = 1L;

    protected volatile Pattern[] includedDocUrlPatterns;

    protected volatile Pattern[] excludedDocUrlPatterns;

    protected transient volatile Map<ConfigName, Map<String, String>> configParameterMap;

    protected CrawlerClientFactory crawlerClientFactory = null;

    public WebConfig() {

 *
 * @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);
  }