}

  @Override
  public T or(T defaultValue) {
    return checkNotNull(defaultValue, "use Optional.orNull() instead of Optional.or(null)");
  }

  @SuppressWarnings("unchecked") // safe covariant cast
  @Override
  public Optional<T> or(Optional<? extends T> secondChoice) {
    return (Optional<T>) checkNotNull(secondChoice);
  }

  @Override
  public T or(Supplier<? extends T> supplier) {

    super(method.getName());
    this.factory = checkNotNull(factory);
    this.data = checkNotNull(data);
    this.expected = checkNotNull(factory.getExpected(data));
    this.suiteName = checkNotNull(suiteName);
    this.caseDesc = checkNotNull(caseDesc);
  }

  @Override
  public String getName() {

  @J2ktIncompatible
  @GwtIncompatible
  public static <T extends @Nullable Object> AsyncCallable<T> asAsyncCallable(
      Callable<T> callable, ListeningExecutorService listeningExecutorService) {
    checkNotNull(callable);
    checkNotNull(listeningExecutorService);
    return () -> listeningExecutorService.submit(callable);
  }

  /**
   * Wraps the given callable such that for the duration of {@link Callable#call} the thread that is

    checkNotNull(edge);
    checkNotNull(node);

    if (isSelfLoop) {
      checkPositive(++selfLoopCount);
    }
    N previousNode = inEdgeMap.put(edge, node);
    checkState(previousNode == null);
  }

  @Override
  public void addOutEdge(E edge, N node) {
    checkNotNull(edge);
    checkNotNull(node);

    N previousNode = outEdgeMap.put(edge, node);

   */
  SubscriberExceptionContext(
      EventBus eventBus, Object event, Object subscriber, Method subscriberMethod) {
    this.eventBus = checkNotNull(eventBus);
    this.event = checkNotNull(event);
    this.subscriber = checkNotNull(subscriber);
    this.subscriberMethod = checkNotNull(subscriberMethod);
  }

  /**
   * @return The {@link EventBus} that handled the event and the subscriber. Useful for broadcasting

    @Override
    public SortedMap<R, Map<C, V>> headMap(R toKey) {
      checkNotNull(toKey);
      return new StandardRowSortedTable<R, C, V>(sortedBackingMap().headMap(toKey), factory)
          .rowMap();
    }

    @Override
    public SortedMap<R, Map<C, V>> subMap(R fromKey, R toKey) {
      checkNotNull(fromKey);
      checkNotNull(toKey);

      // TODO: Remove "ImmutableSet.<E>" when eclipse bug is fixed.
      return ImmutableSet.<E>of(first);
    }

    Set<E> delegate = Sets.newLinkedHashSet();
    delegate.add(checkNotNull(first));
    do {
      delegate.add(checkNotNull(elements.next()));
    } while (elements.hasNext());

    return unsafeDelegate(delegate);
  }

  // Factory methods that skips the null checks on elements, only used when

    super(method.getName());
    this.factory = checkNotNull(factory);
    this.data = checkNotNull(data);
    this.expected = checkNotNull(factory.getExpected(data));
    this.suiteName = checkNotNull(suiteName);
    this.caseDesc = checkNotNull(caseDesc);
  }

  @Override
  public String getName() {

   *     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}.

    checkNotClosed();
    target.append((char) c);
  }

  @Override
  public void write(String str) throws IOException {
    checkNotNull(str);
    checkNotClosed();
    target.append(str);
  }

  @Override
  public void write(String str, int off, int len) throws IOException {
    checkNotNull(str);
    checkNotClosed();
    // tricky: append takes start, end pair...
    target.append(str, off, off + len);
  }