ComparableSubClass node8 = new ComparableSubClass(8);

    graph.addNode(node4);
    graph.addNode(node2);
    graph.addNode(node6);
    graph.addNode(node8);

    assertThat(graph.nodeOrder().comparator()).isEqualTo(Ordering.natural());
    assertThat(graph.nodes()).containsExactly(node2, node4, node6, node8).inOrder();
  }

  private static void addNodes(MutableGraph<Integer> graph) {

     *      org.apache.maven.artifact.resolver.ResolutionNode)
     */

    @Override
    public ResolutionNode resolveConflict(ResolutionNode node1, ResolutionNode node2) {
        return node1.getDepth() <= node2.getDepth() ? node1 : node2;
    }

     *
     * @param node1 the first artifact declaration
     * @param node2 the second artifact declaration
     * @return the artifact declaration to use: <code>node1</code>; <code>node2</code>; or <code>null</code>if
     *         this conflict cannot be resolved
     * @since 3.0
     */
    ResolutionNode resolveConflict(ResolutionNode node1, ResolutionNode node2);

     *      org.apache.maven.artifact.resolver.ResolutionNode)
     */

    @Override
    public ResolutionNode resolveConflict(ResolutionNode node1, ResolutionNode node2) {
        return node1.getDepth() >= node2.getDepth() ? node1 : node2;
    }

     */

    @Override
    public ResolutionNode resolveConflict(ResolutionNode node1, ResolutionNode node2) {
        try {
            ArtifactVersion version1 = node1.getArtifact().getSelectedVersion();
            ArtifactVersion version2 = node2.getArtifact().getSelectedVersion();

            return version1.compareTo(version2) > 0 ? node1 : node2;
        } catch (OverConstrainedVersionException exception) {

     */

    @Override
    public ResolutionNode resolveConflict(ResolutionNode node1, ResolutionNode node2) {
        try {
            ArtifactVersion version1 = node1.getArtifact().getSelectedVersion();
            ArtifactVersion version2 = node2.getArtifact().getSelectedVersion();

            return version1.compareTo(version2) <= 0 ? node1 : node2;
        } catch (OverConstrainedVersionException exception) {

    for (E key : keys) {
      LockGraphNode node = new LockGraphNode(getLockName(key));
      nodes.add(node);
      map.put(key, node);
    }
    // Pre-populate all allowedPriorLocks with nodes of smaller ordinal.
    for (int i = 1; i < numKeys; i++) {
      nodes.get(i).checkAcquiredLocks(Policies.THROW, nodes.subList(0, i));
    }
    // Pre-populate all disallowedPriorLocks with nodes of larger ordinal.

      checkArgument(
          edge.length() == 2, "Expecting each edge to consist of 2 characters but got %s", edge);
      char node1 = edge.charAt(0);
      char node2 = edge.charAt(1);
      graphMapBuilder.put(node1, node2);
      if (!directed) {
        graphMapBuilder.put(node2, node1);
      }
    }
    ImmutableMultimap<Character, Character> graphMap = graphMapBuilder.build();

      checkArgument(
          edge.length() == 2, "Expecting each edge to consist of 2 characters but got %s", edge);
      char node1 = edge.charAt(0);
      char node2 = edge.charAt(1);
      graphMapBuilder.put(node1, node2);
      if (!directed) {
        graphMapBuilder.put(node2, node1);
      }
    }
    ImmutableMultimap<Character, Character> graphMap = graphMapBuilder.build();

    checkNotNull(nodeU);
    checkNotNull(nodeV);
    return nodes().contains(nodeU) && successors(nodeU).contains(nodeV);
  }

  @Override
  public boolean hasEdgeConnecting(EndpointPair<N> endpoints) {
    checkNotNull(endpoints);
    if (!isOrderingCompatible(endpoints)) {
      return false;
    }
    N nodeU = endpoints.nodeU();
    N nodeV = endpoints.nodeV();