assertNotNull(ed);
        assertNotNull(ed.getExportedPackages());
        assertTrue(ed.getExportedPackages().isEmpty());
        assertNotNull(ed.getExportedArtifacts());
        assertTrue(ed.getExportedArtifacts().isEmpty());
    }

    @Test
    void testCompleteDescriptor() throws Exception {
        String xml = "<?xml version='1.0' encoding='UTF-8'?>" + "<extension>" + "<exportedPackages>"

    public ClassRealm getClassRealm() {
        return realm;
    }

    /**
     * Returns artifacts exported by the extension, identified by groupId:artifactId string key.
     */
    public Set<String> getExportedArtifacts() {
        return artifacts;
    }

    /**
     * Returns classpath elements exported by the extension.
     */
    public Set<String> getExportedPackages() {
        return packages;
    }

public class CoreExports {
    private final Set<String> artifacts;

    private final Map<String, ClassLoader> packages;

    public CoreExports(CoreExtensionEntry entry) {
        this(entry.getClassRealm(), entry.getExportedArtifacts(), entry.getExportedPackages());
    }

    public CoreExports(ClassRealm realm, Set<String> exportedArtifacts, Set<String> exportedPackages) {

        if (exportedPackages == null) {
            this.exportedPackages = null;
        } else {
            this.exportedPackages = new ArrayList<>(exportedPackages);
        }
    }

    public List<String> getExportedArtifacts() {
        if (exportedArtifacts == null) {
            exportedArtifacts = new ArrayList<>();
        }

        return exportedArtifacts;
    }

            CoreExtensionEntry coreEntry, List<CoreExtensionEntry> extensionEntries) {
        Set<String> exportedArtifacts = new HashSet<>(coreEntry.getExportedArtifacts());
        for (CoreExtensionEntry extension : extensionEntries) {
            exportedArtifacts.addAll(extension.getExportedArtifacts());
        }
        return exportedArtifacts;
    }

    protected Set<String> collectExportedPackages(

    @Inject
    public DefaultArtifactFilterManager(List<ArtifactFilterManagerDelegate> delegates, CoreExports coreExports) {
        this.delegates = delegates;
        this.coreArtifacts = coreExports.getExportedArtifacts();
    }

    private synchronized Set<String> getExcludedArtifacts() {
        if (excludedArtifacts == null) {
            excludedArtifacts = new LinkedHashSet<>(coreArtifacts);
        }

            if (extensionDescriptor != null) {
                exportedPackages.put(extensionRealm, extensionDescriptor.getExportedPackages());
                exportedArtifacts.put(extensionRealm, extensionDescriptor.getExportedArtifacts());
            }

            if (!plugin.isExtensions()
                    && artifacts.size() == 1
                    && artifacts.get(0).getFile() != null) {
                /*

        } else if (STRATEGY_PLUGIN.equals(classLoadingStrategy)) {
            coreExports.getExportedPackages().forEach((p, cl) -> realm.importFrom(cl, p));
            providedArtifacts = coreExports.getExportedArtifacts();
        } else if (STRATEGY_SELF_FIRST.equals(classLoadingStrategy)) {
            realm.setParentRealm(parentRealm);
        } else {

        } else if (STRATEGY_PLUGIN.equals(classLoadingStrategy)) {
            coreExports.getExportedPackages().forEach((p, cl) -> realm.importFrom(cl, p));
            providedArtifacts = coreExports.getExportedArtifacts();
        } else if (STRATEGY_SELF_FIRST.equals(classLoadingStrategy)) {
            realm.setParentRealm(parentRealm);
        } else {

        apiV4Imports.put("org.slf4j", containerRealm);
        this.maven4ApiRealm = createRealm(API_V4_REALMID, RealmType.Core, null, null, apiV4Imports, null);

        this.providedArtifacts = exports.getExportedArtifacts();

        this.providedArtifactsV4 = providedArtifacts.stream()
                .filter(ga -> ga.startsWith("org.apache.maven:maven-api-"))
                .collect(Collectors.toSet());
    }