}
    }

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

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

import org.eclipse.aether.util.graph.selector.ExclusionDependencySelector;
import org.eclipse.aether.util.graph.transformer.ChainedDependencyGraphTransformer;
import org.eclipse.aether.util.graph.transformer.ConfigurableVersionSelector;
import org.eclipse.aether.util.graph.transformer.ConflictResolver;
import org.eclipse.aether.util.graph.transformer.SimpleOptionalitySelector;
import org.eclipse.aether.util.repository.SimpleArtifactDescriptorPolicy;

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>

```

### Key Design Patterns

- **Factory**: `CrawlerClientFactory`, `ExtractorFactory` - protocol/format-specific component selection
- **Strategy**: `CrawlerClient`, `Extractor`, `Transformer` - pluggable implementations
- **Builder**: `RequestDataBuilder`, `ExtractorBuilder` - fluent construction
- **Template Method**: `AbstractCrawlerClient`, `AbstractExtractor` - common logic with overrides

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

import static java.util.Objects.requireNonNull;

/**
 * Inliner POM transformer. The goal of this transformer is to fix Maven 3 issue about emitting (installing, deploying)
 * unusable POMs when using CI Friendly Versions.
 *
 * @since TBD
 */
@Singleton
@Named

                accessResult.setAccessResultData(null);
                try {
                    final Transformer transformer = ComponentUtil.getComponent(accessResultData.getTransformerName());
                    if (transformer == null) {
                        // no transformer
                        logger.warn("Transformer not found: name={}, url={}", accessResultData.getTransformerName(), accessResult.getUrl());

import org.eclipse.aether.deployment.DeployRequest;
import org.eclipse.aether.installation.InstallRequest;
import org.eclipse.aether.spi.artifact.transformer.ArtifactTransformer;

import static java.util.Objects.requireNonNull;

/**
 * Maven specific transformer.
 */
@Singleton
@Named
final class MavenTransformer implements ArtifactTransformer {
    private final TransformerManager transformerManager;

import org.apache.maven.api.model.Model;

/**
 * A model transformer.
 *
 * @since 4.0.0
 */
@Experimental
public interface ModelTransformer {

    /**
     * Apply a transformation on the file model.
     *
     * @param model the input model
     * @param problems the problem collector to report any issues encountered during transformation
     * @return the transformed model, or the input model if no transformation is needed

        output.cancel(false);
        throw new SomeUncheckedException();
      }
    }
    Transformer transformer = new Transformer();
    SettableFuture<Object> input = SettableFuture.create();

    ListenableFuture<Object> output = transform(input, transformer, directExecutor());
    transformer.output = output;

    input.set("foo");
    assertTrue(output.isCancelled());
  }