* of edges in a graph arranged to form a path (a sequence of adjacent outgoing edges) starting
   * and ending with the same node.
   *
   * <p>This method will detect any non-empty cycle, including self-loops (a cycle of length 1).
   */
  public static <N> boolean hasCycle(Graph<N> graph) {
    int numEdges = graph.edges().size();
    if (numEdges == 0) {
      return false; // An edge-free graph is acyclic by definition.

   * of edges in a graph arranged to form a path (a sequence of adjacent outgoing edges) starting
   * and ending with the same node.
   *
   * <p>This method will detect any non-empty cycle, including self-loops (a cycle of length 1).
   */
  public static <N> boolean hasCycle(Graph<N> graph) {
    int numEdges = graph.edges().size();
    if (numEdges == 0) {
      return false; // An edge-free graph is acyclic by definition.

            assertNull(copy.getSubject(), "Clone should still return null after refresh");
        }
    }

    @Test
    @DisplayName("renew: invokes getSubject and returns self")
    void testRenewInvokesGetSubjectAndReturnsSelf() {
        JAASAuthenticator auth = spy(new JAASAuthenticator());
        // Avoid real JAAS by stubbing getSubject
        doReturn(new Subject()).when(auth).getSubject();

     * environments and only to carry test data.
     *
     * The server’s TLS certificate **does not need to be signed** by a trusted certificate
     * authority. Instead, it will trust any well-formed certificate, even if it is self-signed.
     * This is necessary for testing against localhost or in development environments where a
     * certificate authority is not possible.
     *

            return null;
        }
    }

    // Provide different implementation behaviors to a parameterized test
    static Stream<Arguments> implementations() {
        return Stream.of(Arguments.of("returns self", (Supplier<SmbRenewableCredentials>) SelfRenewingCreds::new, true, false),
                Arguments.of("returns new", (Supplier<SmbRenewableCredentials>) NewRenewingCreds::new, false, true),

        when(config.getPid()).thenReturn(12345);
        when(config.getSendBufferSize()).thenReturn(65536);

        target = new SmbPipeHandleImpl(pipe);
    }

    @Test
    @DisplayName("unwrap returns self for assignable type; throws for incompatible and null")
    void testUnwrap() {
        // Happy path: unwrap to concrete type
        SmbPipeHandleImpl unwrapped = target.unwrap(SmbPipeHandleImpl.class);

      "Collection returned is unexpectedly modifiable";
  static final String ERROR_SELF_LOOP = "self-loops are not allowed";
  static final String ERROR_EDGE_NOT_IN_GRAPH =
      "Should not be allowed to pass an edge that is not an element of the graph.";
  static final String ERROR_ADDED_SELF_LOOP = "Should not be allowed to add a self-loop edge.";
  static final String ERROR_ADDED_PARALLEL_EDGE = "Should not be allowed to add a parallel edge.";

        - label: I commit to help with one of those options 👆
          required: true
  - type: textarea
    id: example
    attributes:
      label: Example Code
      description: |
        Please add a self-contained, [minimal, reproducible, example](https://stackoverflow.com/help/minimal-reproducible-example) with your use case.

 * {@link EndpointPair} of an undirected edge is an unordered pair of nodes ({@link #nodeU()} and
 * {@link #nodeV()}).
 *
 * <p>The edge is a self-loop if, and only if, the two endpoints are equal.
 *
 * @author James Sexton
 * @since 20.0
 */
@Beta
@Immutable(containerOf = {"N"})
public abstract class EndpointPair<N> implements Iterable<N> {

    int successorCount = 0;

    for (EndpointPair<N> incidentEdge : incidentEdges) {
      if (incidentEdge.nodeU().equals(thisNode) && incidentEdge.nodeV().equals(thisNode)) {
        // incidentEdge is a self-loop

        adjacentNodeValues.put(thisNode, new PredAndSucc(successorNodeToValueFn.apply(thisNode)));

        orderedNodeConnectionsBuilder.add(new NodeConnection.Pred<>(thisNode));