public static <V extends @Nullable Object> ListenableFuture<V> immediateCancelledFuture() {
    ListenableFuture<Object> instance = ImmediateCancelledFuture.INSTANCE;
    if (instance != null) {
      return (ListenableFuture<V>) instance;
    }
    return new ImmediateCancelledFuture<>();
  }

  /**

        }
      };

  enum NullListener implements RemovalListener<Object, Object> {
    INSTANCE;

    @Override
    public void onRemoval(RemovalNotification<Object, Object> notification) {}
  }

  enum OneWeigher implements Weigher<Object, Object> {
    INSTANCE;

    @Override
    public int weigh(Object key, Object value) {
      return 1;
    }
  }

        }
      };

  enum NullListener implements RemovalListener<Object, Object> {
    INSTANCE;

    @Override
    public void onRemoval(RemovalNotification<Object, Object> notification) {}
  }

  enum OneWeigher implements Weigher<Object, Object> {
    INSTANCE;

    @Override
    public int weigh(Object key, Object value) {
      return 1;
    }
  }

    /**
     * Creates and returns a new instance of {@link ArrayDeque}.
     *
     * @param <E> the element type of {@link ArrayDeque}
     * @return a new instance of {@link ArrayDeque}
     * @see ArrayDeque#ArrayDeque()
     */
    public static <E> ArrayDeque<E> newArrayDeque() {
        return new ArrayDeque<>();
    }

    /**
     * Creates and returns a new instance of {@link ArrayDeque}.
     *

   * object that equals a set member, but isn't the same instance. This behavior is similar to the
   * way {@code IdentityHashMap} handles key lookups.
   *
   * @since 8.0
   */
  public static <E extends @Nullable Object> Set<E> newIdentityHashSet() {
    return Collections.newSetFromMap(Maps.newIdentityHashMap());
  }

  /**
   * Creates an empty {@code CopyOnWriteArraySet} instance.
   *

            K, V, StrongKeyStrongValueEntry<K, V>, StrongKeyStrongValueSegment<K, V>> {
      private static final Helper<?, ?> INSTANCE = new Helper<>();

      @SuppressWarnings("unchecked")
      static <K, V> Helper<K, V> instance() {
        return (Helper<K, V>) INSTANCE;
      }

      @Override
      public Strength keyStrength() {
        return Strength.STRONG;
      }

      @Override

   */
  public static <K extends Comparable<?>, V> Builder<K, V> reverseOrder() {
    return new Builder<>(Ordering.<K>natural().reverse());
  }

  /**
   * A builder for creating immutable sorted map instances, especially {@code public static final}
   * maps ("constant maps"). Example:
   *
   * {@snippet :
   * static final ImmutableSortedMap<Integer, String> INT_TO_WORD =

    }

    /**
     * Returns the Fess configuration instance.
     *
     * @return the Fess configuration
     */
    @Override
    public FessConfig getFessConfig() {
        return fessConfig;
    }

    /**
     * Returns the logger instance for this class.
     *
     * @return the logger instance
     */
    @Override
    public Logger getLogger() {

   * method returns instances of a different class than {@code factory.get()} does.
   *
   * <p>The multimap is serializable if {@code map}, {@code factory}, the sets generated by {@code
   * factory}, and the multimap contents are all serializable.
   *
   * <p>The multimap is not threadsafe when any concurrent operations update the multimap, even if

   * to {@code statusFuture} <i>in addition to</i> the call you make to {@link #finishToFuture()} or
   * a derivation method <i>on the same instance</i>. This is important because calling {@code
   * statusFuture} alone does not provide a way to close the pipeline.
   */
  public ListenableFuture<?> statusFuture() {