fun visitTree(
        classDetails: ClassDetails,
        classesDir: File,
        jarOutputStream: JarOutputStream,
        visited: MutableSet<ClassDetails>
    ) {

        if (!visited.add(classDetails)) {
            return
        }
        if (classDetails.visited) {
            val fileName = classDetails.outputClassFilename
            val classFile = classesDir.resolve(fileName)

            return g;
        }

        List<MetadataGraphVertex> visited = new ArrayList<>(g.getVertices().size());
        visit(g.getEntry(), visited, g);

        List<MetadataGraphVertex> dropList = new ArrayList<>(g.getVertices().size());

        // collect drop list
        for (MetadataGraphVertex v : g.getVertices()) {
            if (!visited.contains(v)) {
                dropList.add(v);
            }
        }

   *   <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.
   */

        ClasspathContainer cpc;

        List<MetadataGraphVertex> visited;

        // -----------------------------------------------------------------------
        protected ClasspathGraphVisitor(MetadataGraph cleanGraph, ClasspathContainer cpc) {
            this.cpc = cpc;
            this.graph = cleanGraph;

            visited = new ArrayList<>(cleanGraph.getVertices().size());
        }

    )


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();

      } finally {
        currentThread.setName(originalName);
      }
    }
  }

  public void fetch(HttpUrl url) throws IOException {
    // Skip hosts that we've visited many times.
    AtomicInteger hostnameCount = new AtomicInteger();
    AtomicInteger previous = hostnames.putIfAbsent(url.host(), hostnameCount);
    if (previous != null) hostnameCount = previous;

      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,