* Creates a new class realm for the specified build extension.
     *
     * @param extension The extension plugin for which to create a realm, must not be {@code null}.
     * @param artifacts The artifacts to add to the class realm, may be {@code null}. Unresolved artifacts (i.e. with a
     *            missing file) will automatically be excluded from the realm.
     * @return The new extension realm, never {@code null}.
     */

    private final String classifier;

    private final String extension;

    private final String packaging;

    TransformedArtifactHandler(String classifier, String extension, String packaging) {
        this.classifier = classifier;
        this.extension = requireNonNull(extension);
        this.packaging = requireNonNull(packaging);
    }

    @Override

        return create(ArtifactFactoryRequest.build(session, groupId, artifactId, version, extension));
    }

    @Nonnull
    default Artifact create(
            @Nonnull Session session,
            String groupId,
            String artifactId,
            String version,
            String classifier,
            String extension,
            String type) {

            PathType... pathTypes) {
        this.id = requireNonNull(id, "id");
        this.language = requireNonNull(language, "language");
        this.extension = requireNonNull(extension, "extension");
        this.classifier = classifier;
        this.includesDependencies = includesDependencies;
        this.pathTypes = Collections.unmodifiableSet(new HashSet<>(Arrays.asList(pathTypes)));

        Map<String, String> properties = new HashMap<>();

 *       {@link java.util.Set} contract.
 *   <dt>{@link SortedSetMultimap}
 *   <dd>An extension of {@link SetMultimap} for which the {@linkplain SortedSetMultimap#get
 *       collection values} associated with a given key is a {@link java.util.SortedSet}.
 *   <dt>{@link BiMap}
 *   <dd>An extension of {@link java.util.Map} that guarantees the uniqueness of its values as well

import static org.junit.jupiter.api.Assertions.assertTrue;

/**
 * Tests {@code Extension}.
 *
 */
class ExtensionTest {

    @Test
    void testHashCodeNullSafe() {
        new Extension().hashCode();
    }

    @Test
    void testEqualsNullSafe() {
        assertFalse(new Extension().equals(null));

        new Extension().equals(new Extension());
    }

    @Test
    void testEqualsIdentity() {

        return new ByteArrayInputStream(xml.getBytes(StandardCharsets.UTF_8));
    }

    @Test
    void testEmptyDescriptor() throws Exception {
        String xml = "<extension></extension>";

        ExtensionDescriptor ed = builder.build(toStream(xml));

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

 * under the License.
 */
package org.apache.maven.cling.extensions;

import org.apache.maven.api.cli.extensions.CoreExtension;
import org.apache.maven.extension.internal.CoreExtensionEntry;

/**
 * Represents a core extension that has been selected to be loaded.
 * @param coreExtension The extension configuration entry with location tracking.
 * @param entry The loaded entry with descriptor.
 */

 *
 */
class TestArtifactHandler implements ArtifactHandler {

    private String type;

    private String extension;

    TestArtifactHandler(String type) {
        this(type, type);
    }

    TestArtifactHandler(String type, String extension) {
        this.type = type;
        this.extension = extension;
    }

    @Override
    public String getClassifier() {
        return null;
    }

    @Override

@Deprecated
class TestArtifactHandler implements ArtifactHandler {

    private String type;

    private String extension;

    TestArtifactHandler(String type) {
        this(type, type);
    }

    TestArtifactHandler(String type, String extension) {
        this.type = type;
        this.extension = extension;
    }

    @Override
    public String getClassifier() {
        return null;
    }

    @Override