* 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";

        if (build != null) {
            for (Extension extension : build.getExtensions()) {
                Plugin plugin = new Plugin();
                plugin.setGroupId(extension.getGroupId());
                plugin.setArtifactId(extension.getArtifactId());
                plugin.setVersion(extension.getVersion());
                XmlNode configuration = extension.getDelegate().getConfiguration();

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

    @TestMetadata("analysis/analysis-api/testData/referenceResolve/kDoc/extensions")
    @TestDataPath("$PROJECT_ROOT")
    public class Extensions {
      @Test
      public void testAllFilesPresentInExtensions() {
        KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("analysis/analysis-api/testData/referenceResolve/kDoc/extensions"), Pattern.compile("^([^.]+)\\.kt$"), null, true);
      }

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

        assertThat(set.contains(TestRunner.class.getName()), is(true));
        assertThat(set.contains("junit.textui.package-info"), is(false));
        assertThat(set.contains(junit.extensions.TestDecorator.class.getName()), is(not(true)));
    }

        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) {

        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"));

package org.apache.maven.api.spi;

import org.apache.maven.api.annotations.Consumer;
import org.apache.maven.api.annotations.Experimental;

/**
 * Marker interface to indicate services that can be provided by plugins and extensions.
 */
@Experimental
@Consumer

    }

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