*       v2)} implies that {@code Objects.equals(transformer.transform(k1, v1),
     *       transformer.transform(k2, v2))}.
     * </ul>
     *
     * @throws NullPointerException if the key or value is null and this transformer does not accept
     *     null arguments
     */
    @ParametricNullness

     *       v2)} implies that {@code Objects.equals(transformer.transform(k1, v1),
     *       transformer.transform(k2, v2))}.
     * </ul>
     *
     * @throws NullPointerException if the key or value is null and this transformer does not accept
     *     null arguments
     */
    @ParametricNullness

import org.eclipse.aether.RepositorySystemSession;
import org.eclipse.aether.deployment.DeployRequest;
import org.eclipse.aether.installation.InstallRequest;

/**
 * Maven POM transformer.
 * TODO: rename this interface to "Transformer" as it can do much more than just transform POM.
 * @since TBD
 */
public interface PomArtifactTransformer {
    InstallRequest remapInstallArtifacts(RepositorySystemSession session, InstallRequest request);

        }
    }

    static class ExtensionInterpolator extends MavenTransformer {
        ExtensionInterpolator(UnaryOperator<String> transformer) {
            super(transformer);
        }

        public XmlNode transform(XmlNode node) {
            return super.transform(node);
        }
    }

    }

    @Test
    public void test_metaContentMapping() {
        transformer.metaContentMapping = new HashMap<>();
        transformer.metaContentMapping.put("author", "dc:creator");
        transformer.metaContentMapping.put("title", "dc:title");

        assertEquals(2, transformer.metaContentMapping.size());
        assertEquals("dc:creator", transformer.metaContentMapping.get("author"));

    final EntryTransformer<? super K, ? super V1, V2> transformer;

    TransformedEntriesMultimap(
        Multimap<K, V1> fromMultimap, EntryTransformer<? super K, ? super V1, V2> transformer) {
      this.fromMultimap = checkNotNull(fromMultimap);
      this.transformer = checkNotNull(transformer);
    }

    Collection<V2> transform(@ParametricNullness K key, Collection<V1> values) {

    final EntryTransformer<? super K, ? super V1, V2> transformer;

    TransformedEntriesMultimap(
        Multimap<K, V1> fromMultimap, EntryTransformer<? super K, ? super V1, V2> transformer) {
      this.fromMultimap = checkNotNull(fromMultimap);
      this.transformer = checkNotNull(transformer);
    }

    Collection<V2> transform(@ParametricNullness K key, Collection<V1> values) {

        }
    }

    static class ExtensionInterpolator extends MavenTransformer {
        ExtensionInterpolator(UnaryOperator<String> transformer) {
            super(transformer);
        }

        public XmlNode transform(XmlNode node) {
            return super.transform(node);
        }
    }

import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;

/**
 * Constants used in the fess-crawler.
 * This class provides a collection of constant values for HTTP methods, status codes,
 * transformer names, boolean values, character encodings, date/time formats, and XML features.
 * It is designed to avoid the instantiation.
 */
public final class Constants {
    /**
     * The GET method.
     */

<!DOCTYPE components PUBLIC "-//DBFLUTE//DTD LastaDi 1.0//EN"
	"http://dbflute.org/meta/lastadi10.dtd">
<components namespace="fessCrawler">
	<include path="crawler/container.xml" />
	<include path="crawler/transformer.xml" />

	<component name="ruleManager"
		class="org.codelibs.fess.crawler.rule.impl.RuleManagerImpl" instance="prototype">
		<postConstruct name="addRule">
			<arg>sitemapsRule</arg>
		</postConstruct>