@Override
  @Test
  public void nodes_checkReturnedSetMutability() {
    assume().that(graphIsMutable()).isTrue();

    Set<Integer> nodes = graph.nodes();
    UnsupportedOperationException e =
        assertThrows(UnsupportedOperationException.class, () -> nodes.add(N2));
    addNode(N1);
    assertThat(graph.nodes()).containsExactlyElementsIn(nodes);
  }

  @Override
  @Test

 * encounter a call to {@code reverse}, continue working backwards until a result is determined, and
 * then reverse that result.
 *
 * <h3>Additional notes</h3>
 *
 * <p>Except as noted, the orderings returned by the factory methods of this class are serializable
 * if and only if the provided instances that back them are. For example, if {@code ordering} and

 * with user-defined properties.
 *
 * <p>A {@code ValueGraph} built by this class has the following default properties:
 *
 * <ul>
 *   <li>does not allow self-loops
 *   <li>orders {@link ValueGraph#nodes()} in the order in which the elements were added (insertion
 *       order)
 * </ul>
 *
 * <p>{@code ValueGraph}s built by this class also guarantee that each collection-returning accessor

     * Shortcut for {@code getService(DependencyResolver.class).flatten(...)}.
     *
     * @param node node for which to get a flattened list
     * @param scope build path scope (main compile, test compile, etc.) of desired nodes
     * @return flattened list of node with the given build path scope
     * @throws org.apache.maven.api.services.DependencyResolverException if the dependency flattening failed
     *

      assertThat(network.nodes()).isEmpty();
      assertThat(network.edges()).isEmpty();
      AbstractNetworkTest.validateNetwork(network);

      while (network.nodes().size() < NUM_NODES) {
        network.addNode(gen.nextInt(NODE_POOL_SIZE));
      }
      ArrayList<Integer> nodeList = new ArrayList<>(network.nodes());
      for (int i = 0; i < NUM_EDGES; ++i) {

    assertThat(graph.nodes()).contains(N1);
  }

  @Test
  public void addNode_existingNode() {
    assume().that(graphIsMutable()).isTrue();

    addNode(N1);
    ImmutableSet<Integer> nodes = ImmutableSet.copyOf(graph.nodes());
    assertThat(graphAsMutableGraph.addNode(N1)).isFalse();
    assertThat(graph.nodes()).containsExactlyElementsIn(nodes);
  }

  @Test

    assertThat(graph.nodes()).containsExactly(3, 1, 4).inOrder();
  }

  // The default ordering is INSERTION unless otherwise specified.
  @Test
  public void nodeOrder_default() {
    MutableGraph<Integer> graph = GraphBuilder.directed().build();

    addNodes(graph);

    assertThat(graph.nodeOrder()).isEqualTo(insertion());
    assertThat(graph.nodes()).containsExactly(3, 1, 4).inOrder();
  }

    }
  }

  @Override
  @Test
  public void nodes_checkReturnedSetMutability() {
    assume().that(graphIsMutable()).isTrue();

    Set<Integer> nodes = network.nodes();
    UnsupportedOperationException e =
        assertThrows(UnsupportedOperationException.class, () -> nodes.add(N2));
    addNode(N1);
    assertThat(network.nodes()).containsExactlyElementsIn(nodes);
  }

  @Override
  @Test

/**
 * MetadataGraph node - as it's a directed graph - holds adjacency lists for incident and exident nodes
 *
 *
 */
@Deprecated
public class MetadataGraphNode {
    /** node payload */
    MavenArtifactMetadata metadata;

    /** nodes, incident to this (depend on me) */
    List<MetadataGraphNode> inNodes;

    /** nodes, exident to this (I depend on) */
    List<MetadataGraphNode> exNodes;

   *
   * <p><b>Note:</b> this method does not return the number of <i>distinct elements</i> in the
   * multiset, which is given by {@code entrySet().size()}.
   */
  @Override
  int size();

  /**
   * Returns the number of occurrences of an element in this multiset (the <i>count</i> of the
   * element). Note that for an {@link Object#equals}-based multiset, this gives the same result as