} // -- String getClassLoadingStrategy()

    /**
     * Get the group ID of the extension's artifact.
     *
     * @return String
     */
    public String getGroupId() {
        return this.groupId;
    } // -- String getGroupId()

    /**
     * Get the version of the extension.
     *
     * @return String
     */
    public String getVersion() {
        return this.version;

    }

    private CoreExtensionEntry createExtension(CoreExtension extension, List<Artifact> artifacts) throws Exception {
        String realmId = "coreExtension>" + extension.getGroupId() + ":" + extension.getArtifactId() + ":"
                + extension.getVersion();
        final ClassRealm realm = classWorld.newRealm(realmId, null);
        Set<String> providedArtifacts = Collections.emptySet();

    }

    private CoreExtensionEntry createExtension(CoreExtension extension, List<Artifact> artifacts) throws Exception {
        String realmId = "coreExtension>" + extension.getGroupId() + ":" + extension.getArtifactId() + ":"
                + extension.getVersion();
        final ClassRealm realm = classWorld.newRealm(realmId, null);
        Set<String> providedArtifacts = Collections.emptySet();

        }

        return null;
    }

    @Override
    public List<String> findVersions(Artifact artifact) {
        List<String> versions = getProjects()
                .getOrDefault(artifact.getGroupId(), Collections.emptyMap())
                .getOrDefault(artifact.getArtifactId(), Collections.emptyMap())
                .values()
                .stream()
                .map(MavenProject::getVersion)

        requireNonNull(path, "path cannot be null");
        if (artifact.getGroupId().isEmpty()
                || artifact.getArtifactId().isEmpty()
                || artifact.getBaseVersion().toString().isEmpty()) {
            artifact = session.createProducedArtifact(
                    artifact.getGroupId().isEmpty() ? project.getGroupId() : artifact.getGroupId(),

                }
                Artifact result = new RelocatedArtifact(
                        original,
                        isAny(relocation.target.getGroupId()) ? null : relocation.target.getGroupId(),
                        isAny(relocation.target.getArtifactId()) ? null : relocation.target.getArtifactId(),

        Artifact pomArtifact = artifact;

        if (!pomArtifact.getClassifier().isEmpty() || !"pom".equals(pomArtifact.getExtension())) {
            pomArtifact =
                    new DefaultArtifact(artifact.getGroupId(), artifact.getArtifactId(), "pom", artifact.getVersion());
        }

        return pomArtifact;
    }

    /**

                if (deployBuildPom) {
                    // Add the main POM as a build POM with "build" classifier
                    result.add(new DefaultArtifact(
                            main.getGroupId(),
                            main.getArtifactId(),
                            BUILD_POM_CLASSIFIER,
                            main.getExtension(),
                            main.getVersion(),

            return model.getId();
        }

        return "";
    }

    static String getGroupId(Model model) {
        String groupId = model.getGroupId();
        if (groupId == null && model.getParent() != null) {
            groupId = model.getParent().getGroupId();
        }
        return groupId;
    }

    static String getVersion(Model model) {

                .flatMap(container -> container != null ? container.getPlugins().stream() : Stream.empty())
                .filter(p -> !request.getPluginGroups().contains(p.getGroupId()))
                .collect(Collectors.groupingBy(
                        Plugin::getGroupId,
                        LinkedHashMap::new,
                        Collectors.mapping(Plugin::getArtifactId, Collectors.toSet())));