static final String ERROR_ELEMENT_REMOVED = "used to generate this set";
  private static final String NODE_STRING = "Node";
  private static final String EDGE_STRING = "Edge";

  enum EdgeType {
    UNDIRECTED,
    DIRECTED;
  }

  private TestUtil() {}

  static void assertNodeNotInGraphErrorMessage(Throwable throwable) {
    assertThat(throwable).hasMessageThat().startsWith(NODE_STRING);

  /**
   * Returns the node that is adjacent to the origin node along {@code edge}.
   *
   * <p>In the directed case, {@code edge} is assumed to be an outgoing edge.
   */
  N adjacentNode(E edge);

  /**
   * Remove {@code edge} from the set of incoming edges. Returns the former predecessor node.
   *
   * <p>In the undirected case, returns {@code null} if {@code isSelfLoop} is true.
   */
  @CanIgnoreReturnValue

    /**
     * Handles the prologue phase of action execution.
     * <p>
     * This method catches UserRoleLoginException and redirects to the
     * appropriate action class.
     * </p>
     *
     * @param runtime the action runtime context
     * @return the action response, or redirect response if login exception occurs
     */
    @Override
    public ActionResponse godHandPrologue(final ActionRuntime runtime) {

  private static final int NODE_POOL_SIZE = 1000; // must be >> NUM_NODES

  @Test
  public void directedGraph() {
    testGraphMutation(GraphBuilder.directed());
  }

  @Test
  public void undirectedGraph() {
    testGraphMutation(GraphBuilder.undirected());
  }

  private static void testGraphMutation(GraphBuilder<? super Integer> graphBuilder) {

    //                                                                      Search Execute
    //                                                                      ==============

    /**
     * Handles user logout and redirects to the login page.
     *
     * @return the HTML response after logout
     */
    @Execute
    public HtmlResponse index() {
        final OptionalThing<FessUserBean> userBean = getUserBean();

   * * It may be the request generated in response to an HTTP redirect or authentication
   *   challenge. In this case the request URL may be different than the initial request URL.
   *
   * Use the `request` of the [networkResponse] field to get the wire-level request that was
   * transmitted. In the case of follow-ups and redirects, also look at the `request` of the

     * @param name The generator name.
     */
    public void setName(final String name) {
        this.name = name;
    }

    /**
     * Sets the maximum number of redirects to follow.
     * @param maxRedirectCount The maximum redirect count.
     */
    public void setMaxRedirectCount(final int maxRedirectCount) {
        this.maxRedirectCount = maxRedirectCount;
    }

     */
    public void setRoutePlanner(final HttpRoutePlanner routePlanner) {
        this.routePlanner = routePlanner;
    }

    /**
     * Sets whether HTTP redirects are enabled.
     *
     * @param redirectsEnabled True to enable redirects, false otherwise
     */
    public void setRedirectsEnabled(final boolean redirectsEnabled) {
        this.redirectsEnabled = redirectsEnabled;
    }

    /**

    method: String,
  ): Request? {
    // Does the client allow redirects?
    if (!client.followRedirects) return null

    val location = userResponse.header("Location") ?: return null
    // Don't follow redirects to unsupported protocols.
    val url = userResponse.request.url.resolve(location) ?: return null

    // If configured, don't follow redirects between SSL and non-SSL.

    }

    /**
     * Redirects the user to the root path of the application.
     *
     * @return HTML response that redirects to the root page
     */
    protected HtmlResponse redirectToRoot() {
        return systemHelper.getRedirectResponseToRoot(newHtmlResponseAsRedirect("/"));
    }

    /**