*   <li>While traversing, the traverser will use <i>O(n)</i> space (where <i>n</i> is the number
   *       of nodes that have thus far been visited), plus <i>O(H)</i> space (where <i>H</i> is the
   *       number of nodes that have been seen but not yet visited, that is, the "horizon").
   * </ul>
   *
   * @param graph {@link SuccessorsFunction} representing a general graph that may have cycles.
   */

   *
   * Visited Nodes = {}
   * EndpointPair [N1, N2] - return
   * EndpointPair [N1, N3] - return
   * Visited Nodes = {N1}
   * EndpointPair [N2, N1] - skip
   * EndpointPair [N2, N3] - return
   * Visited Nodes = {N1, N2}
   * EndpointPair [N3, N1] - skip
   * EndpointPair [N3, N2] - skip
   * Visited Nodes = {N1, N2, N3}
   * EndpointPair [N4, N4] - return
   * Visited Nodes = {N1, N2, N3, N4}

 * class CrawlingService extends AbstractScheduledService {
 *   private Set<Uri> visited;
 *   private Queue<Uri> toCrawl;
 *   protected void startUp() throws Exception {
 *     toCrawl = readStartingUris();
 *   }
 *
 *   protected void runOneIteration() throws Exception {
 *     Uri uri = toCrawl.remove();
 *     Collection<Uri> newUris = crawl(uri);
 *     visited.add(uri);
 *     for (Uri newUri : newUris) {

            [Guava's philosophy](https://github.com/google/guava/wiki/PhilosophyExplained), and
            I strongly believe that this proposal aligns with it.
          required: true
        - label: >
            I have visited the [idea graveyard](https://github.com/google/guava/wiki/IdeaGraveyard),
            and did not see anything similar to this idea.

        private int indexToRemove = ABSENT;
        private int expectedModCount = biMap.modCount;

        // Calls to setValue on inverse entries can move already-visited entries to the end.
        // Make sure we don't visit those.
        private int remaining = biMap.size;

        private void checkForComodification() {
          if (biMap.modCount != expectedModCount) {

     * @param packagePrefix resource path prefix inside {@code classloader} for any files found
     *     under {@code directory}
     * @param currentPath canonical files already visited in the current directory tree path, for
     *     cycle elimination
     */
    private void scanDirectory(
        File directory,
        String packagePrefix,
        Set<File> currentPath,

        map(new TypeVariableKey(vars[i]), typeArgs[i]);
      }
      visit(rawClass);
      visit(parameterizedType.getOwnerType());
    }

    @Override
    void visitTypeVariable(TypeVariable<?> t) {
      visit(t.getBounds());
    }

    @Override
    void visitWildcardType(WildcardType t) {
      visit(t.getUpperBounds());
    }

    private void map(TypeVariableKey var, Type arg) {

/**
 * A TimeLimiter implementation which actually does not attempt to limit time at all. This may be
 * desirable to use in some unit tests. More importantly, attempting to debug a call which is
 * time-limited would be extremely annoying, so this gives you a time-limiter you can easily swap in
 * for your real time-limiter while you're debugging.
 *
 * @author Kevin Bourrillion
 * @author Jens Nyman
 * @since 1.0
 */

   * rate limiter is unused, bursts of up to {@code permitsPerSecond} permits will be allowed, with
   * subsequent requests being smoothly limited at the stable rate of {@code permitsPerSecond}.
   *
   * @param permitsPerSecond the rate of the returned {@code RateLimiter}, measured in how many
   *     permits become available per second

  final Collection<? extends Throwable> exceptions;

  private ClusterException(Collection<? extends Throwable> exceptions) {
    super(
        exceptions.size() + " exceptions were thrown. The first exception is listed as a cause.",
        exceptions.iterator().next());
    ArrayList<? extends Throwable> temp = new ArrayList<>(exceptions);
    this.exceptions = Collections.unmodifiableCollection(temp);
  }