*   <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.
   */

    }

    public void analyzePom(Model model) {
        totalPoms++;
        Set<Object> visited = new HashSet<>();
        processModelNode(model, "/project", "project", visited);
    }

    private void processModelNode(Object node, String currentPath, String elementName, Set<Object> visited) {
        if (node == null || !visited.add(node)) {
            return;
        }

        Class<?> clazz = node.getClass();

    )


def get_flat_dependant(
    dependant: Dependant,
    *,
    skip_repeats: bool = False,
    visited: list[DependencyCacheKey] | None = None,
    parent_oauth_scopes: list[str] | None = None,
) -> Dependant:
    if visited is None:
        visited = []
    visited.append(dependant.cache_key)
    use_parent_oauth_scopes = (parent_oauth_scopes or []) + (
        dependant.oauth_scopes or []
    )

        // TODO use cache
    }

    /**
     * Checks if a URL has been visited by looking in both the queue and access results.
     *
     * @param urlQueue The URL queue entry to check.
     * @return true if the URL has been visited, false otherwise.
     */
    @Override
    public boolean visited(final OpenSearchUrlQueue urlQueue) {
        final String url = urlQueue.getUrl();

                throw new ArtifactDescriptorException(result);
            }

            if (!visited.add(a.getGroupId() + ':' + a.getArtifactId() + ':' + a.getBaseVersion())) {
                RepositoryException exception =
                        new RepositoryException("Artifact relocations form a cycle: " + visited);
                invalidDescriptor(session, trace, a, exception);

      return true;
    }
    return hasCycle(network.asGraph());
  }

  /**
   * Performs a traversal of the nodes reachable from {@code startNode}. If we ever reach a node
   * we've already visited (following only outgoing edges and without reusing edges), we know
   * there's a cycle in the graph.
   */
  private static <N> boolean subgraphHasCycle(

 * 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) {

     * @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,

            return null;
        }

        @Override
        public void saveSession(String sessionId) {
            // Do nothing in test
        }

        @Override
        public boolean visited(OpenSearchUrlQueue urlQueue) {
            return false;
        }

        @Override
        public void generateUrlQueues(String sessionId, String url) {
            // Do nothing in test
        }

        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) {