*
     * All that said, don't forget that everyone should call converter.convert() instead of
     * converter.apply(), anyway. If clients use only converter.convert(), then their nullness
     * checkers are unlikely to ever look at the annotations on this declaration.
     *
     * Historical note: At one point, we'd declared this method as accepting and returning nullable
     * values. For details on that, see earlier revisions of this file.
     */

                  for (Integer node : network.nodes()) {
                    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);

                  for (Integer node : network.nodes()) {
                    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);

    // for 5.5 seconds happens about 2% of the time.
    boolean longWait = TimeUnit.NANOSECONDS.toSeconds(thread.timeSpentBlocked) >= 5;
    // Count how long it actually took to return; we'll accept any number between the expected delay
    // and the approximate actual delay, to be robust to variance in thread scheduling.
    char overWaitNanosFirstDigit =
        Long.toString(

   * }</pre>
   */
  private static final SuccessorsFunction<Character> TREE =
      createDirectedGraph("hd", "he", "hg", "da", "db", "dc", "gf");

  /**
   * Two disjoint tree-shaped graphs that look as follows (all edges are directed facing downwards):
   *
   * <pre>{@code
   * a   c
   * |   |
   * |   |
   * b   d
   * }</pre>
   */

   * - method reference: Inside Google, CacheBuilder is used from the implementation of a custom
   *   ClassLoader that is sometimes used as a system classloader. That's a problem because
   *   method-reference linking tries to look up the system classloader, and it fails because there
   *   isn't one yet.
   *
   * - lambda: Outside Google, we got a report of a similar problem in
   *   https://github.com/google/guava/issues/6565
   */

        try {
            return createProtwordsItem(this, form, hook);
        } catch (final ValidationErrorException e) {
            saveToken();
            throw e;
        }
    }

    public static OptionalEntity<ProtwordsItem> createProtwordsItem(final FessBaseAction action, final CreateForm form,
            final VaErrorHook hook) {

    @Override
    synchronized void addShutdownHook(Thread hook) {
      hooks.add(hook);
    }

    synchronized void shutdown() throws InterruptedException {
      for (Thread hook : hooks) {
        hook.start();
      }
      for (Thread hook : hooks) {
        hook.join();
      }
    }
  }

  /* Half of a 1-second timeout in nanoseconds */

        }
        return OptionalEntity.empty();
    }

    protected OptionalEntity<StemmerOverrideItem> createStemmerOverrideItem(final CreateForm form, final VaErrorHook hook) {
        try {
            return createStemmerOverrideItem(this, form, hook);
        } catch (final ValidationErrorException e) {
            saveToken();
            throw e;
        }
    }

        try {
            return createKuromojiItem(this, form, hook);
        } catch (final ValidationErrorException e) {
            saveToken();
            throw e;
        }
    }

    public static OptionalEntity<KuromojiItem> createKuromojiItem(final FessBaseAction action, final CreateForm form,
            final VaErrorHook hook) {