* same class realm is used to load build extensions and load mojos for extensions=true plugins.
     * </p>
     * <strong>Note:</strong> This is part of internal implementation and may be changed or removed without notice
     *
     * @since 3.3.0
     */
    public static final String KEY_EXTENSIONS_REALMS = DefaultMavenPluginManager.class.getName() + "/extensionsRealms";

 */
@Deprecated
public interface ArtifactFilterManager {
    /**
     * Returns a filter for core + extension artifacts.
     *
     * @return the artifact filter
     * @deprecated use {@code META-INF/maven/extension.xml} to define artifacts exported by Maven core and plugin
     *             extensions.
     */
    ArtifactFilter getArtifactFilter();

    /**
     * Returns a filter for only the core artifacts.

 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven;

import java.util.Set;

/**
 * @deprecated use {@code META-INF/maven/extension.xml} to define artifacts exported by Maven core extensions.
 */
@Deprecated
public interface ArtifactFilterManagerDelegate {

    void addExcludes(Set<String> excludes);

    void addCoreExcludes(Set<String> excludes);

// CHECKSTYLE_OFF: RegexpHeader
/**
 * <a href="https://maven.apache.org/resolver/">Maven Resolver</a> extensions for utilizing the Maven POM and Maven
 * repository metadata.
 */

        if (lookup == null) {
            return customLifecycles != null ? customLifecycles : new HashMap<>();
        }

        // Lifecycles cannot be cached as extensions might add custom lifecycles later in the execution.
        try {
            Map<String, Lifecycle> lifecycles = new HashMap<>(lookup.lookupMap(Lifecycle.class));
            for (org.apache.maven.api.Lifecycle lf : registry) {

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * A type implemented by, or extended by maven plugins or extensions.
 * Maven plugins or extensions may provide implementations of those types which will be used by maven.
 * <p>
 * A type can be marked {@link Consumer} or {@link Provider} but not both. A type is assumed to be

        PomTestWrapper pom = buildPom("build-extension-inheritance/sub");
        assertEquals(3, ((List<?>) pom.getValue("build/extensions")).size());
        assertEquals("b", pom.getValue("build/extensions[1]/artifactId"));
        assertEquals("a", pom.getValue("build/extensions[2]/artifactId"));
        assertEquals("0.2", pom.getValue("build/extensions[2]/version"));

     *
     * @param classRealm The class realm hosting the build extensions of this project, may be {@code null}.
     */
    public void setClassRealm(ClassRealm classRealm) {
        this.classRealm = classRealm;
    }

    /**
     * Gets the project's class realm. This class realm hosts the build extensions of the project.

    }

    private static String getKey(Plugin plugin, boolean extension) {
        String version = ArtifactUtils.toSnapshotVersion(plugin.getVersion());
        return (extension ? "extension>" : "plugin>") + plugin.getGroupId() + ":" + plugin.getArtifactId() + ":"
                + version;
    }

        return plugins.keySet();
    }

    /**
     * Performs a lookup using Plexus API to make sure we can look up only "visible" (see Maven classloading) components
     * from current module and for example not extensions coming from other modules.
     */
    private LifecycleMapping lookupLifecycleMapping(final String packaging) {
        return lookup.lookupOptional(LifecycleMapping.class, packaging).orElse(null);
    }