*     the thread's interrupt status is set
   * @since 11.0
   */
  @GwtIncompatible // Futures
  public ListenableFuture<V> reload(K key, V oldValue) throws Exception {
    checkNotNull(key);
    checkNotNull(oldValue);
    return Futures.immediateFuture(load(key));
  }

  /**
   * Computes or retrieves the values corresponding to {@code keys}. This method is called by {@link
   * LoadingCache#getAll}.

          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction,
          BinaryOperator<V> mergeFunction) {
    checkNotNull(keyFunction);
    checkNotNull(valueFunction);
    checkNotNull(mergeFunction);
    return Collectors.collectingAndThen(
        Collectors.toMap(keyFunction, valueFunction, mergeFunction, LinkedHashMap::new),
        ImmutableMap::copyOf);
  }

      return result;
    }
    return new UnmodifiableMultiset<>(checkNotNull(multiset));
  }

  /**
   * Simply returns its argument.
   *
   * @deprecated no need to use this
   * @since 10.0
   */
  @Deprecated
  public static <E> Multiset<E> unmodifiableMultiset(ImmutableMultiset<E> multiset) {
    return checkNotNull(multiset);
  }

    this.value = value;
  }

  @Override
  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
  public void addListener(Runnable listener, Executor executor) {
    checkNotNull(listener, "Runnable was null.");
    checkNotNull(executor, "Executor was null.");
    try {
      executor.execute(listener);
    } catch (Exception e) { // sneaky checked exception

      String relationshipName,
      String hashName,
      ItemReporter itemReporter) {
    this.equivalence = checkNotNull(equivalence);
    this.relationshipName = checkNotNull(relationshipName);
    this.hashName = checkNotNull(hashName);
    this.itemReporter = checkNotNull(itemReporter);
  }

  // TODO(cpovirk): should we reject null items, since the tests already check null automatically?
  @CanIgnoreReturnValue

      BoundType fromBoundType,
      @ParametricNullness E toElement,
      BoundType toBoundType) {
    // These are checked elsewhere, but NullPointerTester wants them checked eagerly.
    checkNotNull(fromBoundType);
    checkNotNull(toBoundType);
    return tailMultiset(fromElement, fromBoundType).headMultiset(toElement, toBoundType);
  }

  abstract Iterator<Entry<E>> descendingEntryIterator();

      cachingHashMap.remove(key);
      return null;
    }
  }

  @CanIgnoreReturnValue
  @Override
  public V put(K key, V value) {
    checkNotNull(key);
    checkNotNull(value);
    Timestamped<V> oldValue = cachingHashMap.put(key, new Timestamped<V>(value, ticker));
    if (oldValue == null) {
      return null;
    }

    return new Joiner(this) {
      @Override
      public <A extends Appendable> A appendTo(
          A appendable, Iterator<? extends @Nullable Object> parts) throws IOException {
        checkNotNull(appendable, "appendable");
        checkNotNull(parts, "parts");
        while (parts.hasNext()) {
          Object part = parts.next();
          if (part != null) {
            appendable.append(Joiner.this.toString(part));

   */
  public static <T extends @Nullable Object> Iterable<T> filter(
      final Iterable<T> unfiltered, final Predicate<? super T> retainIfTrue) {
    checkNotNull(unfiltered);
    checkNotNull(retainIfTrue);
    return new FluentIterable<T>() {
      @Override
      public Iterator<T> iterator() {
        return Iterators.filter(unfiltered.iterator(), retainIfTrue);
      }
    };

   * {@code b} have no common prefix, returns the empty string.
   *
   * @since 11.0
   */
  public static String commonPrefix(CharSequence a, CharSequence b) {
    checkNotNull(a);
    checkNotNull(b);

    int maxPrefixLength = Math.min(a.length(), b.length());
    int p = 0;
    while (p < maxPrefixLength && a.charAt(p) == b.charAt(p)) {
      p++;
    }