* @param model The model to wrap, may be {@code null}.
     */
    ModelData(ModelSource source, Model model) {
        this.source = source;
        this.model = model;
    }

    /**
     * Creates a new container for the specified model.
     *
     * @param model The model to wrap, may be {@code null}.
     * @param groupId The effective group identifier of the model, may be {@code null}.

     *            information along, may be <code>null</code>.
     */
    public void merge(Model target, Model source, boolean sourceDominant, Map<?, ?> hints) {
        Objects.requireNonNull(target, "target cannot be null");

        if (source == null) {
            return;
        }

        Map<Object, Object> context = new HashMap<>();
        if (hints != null) {
            context.putAll(hints);
        }

                new DefaultType(Type.POM, Language.NONE, "pom", null, false),
                new DefaultType(Type.BOM, Language.NONE, "pom", null, false),
                new DefaultType(Type.MAVEN_PLUGIN, Language.JAVA_FAMILY, "jar", null, false, JavaPathType.CLASSES),
                // Java types
                new DefaultType(
                        Type.JAR, Language.JAVA_FAMILY, "jar", null, false, JavaPathType.CLASSES, JavaPathType.MODULES),

        return Stream.of(
                Arguments.of(null, null, null),
                Arguments.of("", "", ""),
                Arguments.of(null, "artifactId", "1.0"),
                Arguments.of("", "artifactId", "1.0"),
                Arguments.of("groupId", null, "1.0"),
                Arguments.of("groupId", "", "1.0"),
                Arguments.of("groupId", "artifactId", null),

                Prerequisites prerequisites =
                        mavenProject.getModel().getDelegate().getPrerequisites();
                if (prerequisites != null && prerequisites.getMaven() != null) {
                    logger.warn(
                            "The project {} uses prerequisites"
                                    + " which is only intended for maven-plugin projects "

    "input": "xn--a",
    "output": null
  },
  {
    "input": "xn--a.xn--zca",
    "output": null
  },
  {
    "input": "xn--a.ß",
    "output": null
  },
  {
    "input": "xn--ls8h=",
    "output": null
  },
  {
    "comment": "Invalid Punycode (contains non-ASCII character)",
    "input": "xn--tešla",
    "output": null
  },
  {
    "comment": "Valid Punycode",

        TreeMultimap.create(StringLength.COMPARATOR, DECREASING_INT_COMPARATOR);
    multimap.put("google", 2);
    multimap.put("google", 6);
    multimap.put(null, 3);
    multimap.put(null, 1);
    multimap.put(null, 7);
    multimap.put("tree", 0);
    multimap.put("tree", null);
    return multimap;
  }

  /** Test that a TreeMultimap created from another uses the natural ordering. */

            Element build = moduleBRoot.child("build").orElse(null);
            Element plugins = build.child("plugins").orElse(null);
            Element plugin = plugins.child("plugin").orElse(null);
            Element dependencies = plugin.child("dependencies").orElse(null);
            Element dependency = dependencies.child("dependency").orElse(null);

            // Apply dependency inference

        requireNonNull(event, "event cannot be null");

        if (!isLocalRepositoryArtifactOrMissing(event.getSession(), event.getArtifact())) {
            return;
        }

        RequestTrace trace = event.getTrace();

        CollectStepData collectStepTrace = null;
        ArtifactRequest artifactRequest = null;
        ArtifactDescriptorRequest artifactDescriptorRequest = null;
        Plugin plugin = null;

     *
     * @param activeProfileIds The identifiers of those profiles to activate, may be {@code null}.
     * @return This context, never {@code null}.
     */
    public DefaultProfileActivationContext setActiveProfileIds(List<String> activeProfileIds) {
        if (activeProfileIds != null) {
            this.activeProfileIds = Collections.unmodifiableList(activeProfileIds);
        } else {