*
 * <p>Applications are encouraged to use a {@code CycleDetectingLockFactory} to create any locks for
 * which external/unmanaged code is executed while the lock is held. (See caveats under
 * <strong>Performance</strong>).
 *
 * <p><strong>Cycle Detection</strong>
 *
 * <p>Deadlocks can arise when locks are acquired in an order that forms a cycle. In a simple

 * <p>
 * <strong>NOTE:</strong> This class is not part of any public api and can be changed or deleted without prior notice.
 *
 * @since 4.0.0
 */
public abstract class Task {

    private final String value;

    public Task(String value) {
        this.value = Objects.requireNonNull(value, "value");
    }

    public String getValue() {
        return value;
    }

 * artifact and does not contain any runtime specific data. The cache must not be used for descriptors that hold runtime
 * data like the plugin realm. <strong>Warning:</strong> This is an internal utility interface that is only public for
 * technical reasons, it is not part of the public API. In particular, this interface can be changed or deleted without
 * prior notice.
 *
 * @since 3.0

  private static final CacheLoader<Key, String> KEY_TO_STRING_LOADER =
      new CacheLoader<Key, String>() {
        @Override
        public String load(Key key) {
          return key.toString();
        }
      };

  private CacheBuilderFactory factoryWithAllKeyStrengths() {
    return new CacheBuilderFactory()
        .withKeyStrengths(ImmutableSet.of(STRONG, Strength.WEAK))

      // Find URL pointing to Finalizer.class file.
      String finalizerPath = FINALIZER_CLASS_NAME.replace('.', '/') + ".class";
      URL finalizerUrl = getClass().getClassLoader().getResource(finalizerPath);
      if (finalizerUrl == null) {
        throw new FileNotFoundException(finalizerPath);
      }

      // Find URL pointing to base of class path.
      String urlString = finalizerUrl.toString();

      // Find URL pointing to Finalizer.class file.
      String finalizerPath = FINALIZER_CLASS_NAME.replace('.', '/') + ".class";
      URL finalizerUrl = getClass().getClassLoader().getResource(finalizerPath);
      if (finalizerUrl == null) {
        throw new FileNotFoundException(finalizerPath);
      }

      // Find URL pointing to base of class path.
      String urlString = finalizerUrl.toString();

/**
 * Provides metadata about a build extension. <strong>Warning:</strong> This is an internal utility class that is only
 * public for technical reasons, it is not part of the public API. In particular, this class can be changed or deleted
 * without prior notice.
 *
 */
public class ExtensionDescriptor {

    private List<String> exportedPackages;

    private List<String> exportedArtifacts;

    ExtensionDescriptor() {

import org.apache.maven.execution.MavenSession;
import org.eclipse.aether.RepositorySystemSession;

/**
 * Helps to provide backward-compatibility with plugins that use legacy components. <strong>Warning:</strong> This is an
 * internal utility interface that is only public for technical reasons, it is not part of the public API. In
 * particular, this interface can be changed or deleted without prior notice.
 *
 * @since 3.0

      MapMaker builder) {
    if (builder.getKeyStrength() == Strength.STRONG
        && builder.getValueStrength() == Strength.STRONG) {
      return new MapMakerInternalMap<>(builder, StrongKeyStrongValueEntry.Helper.<K, V>instance());
    }
    if (builder.getKeyStrength() == Strength.STRONG
        && builder.getValueStrength() == Strength.WEAK) {

package org.apache.maven.execution;

import org.apache.maven.plugin.MojoExecutionException;

/**
 * <p>
 * Extension point that allows build extensions observe and possibly veto mojo executions.
 * </p>
 * <strong>Note:</strong> This interface is part of work in progress and can be changed or removed without notice.
 *
 * @see org.apache.maven.execution.scope.WeakMojoExecutionListener
 * @since 3.1.2
 */