}
        }

        /*
         * NOTE: This is primarily to keep backward-compat with Maven 2.x which did not validate that dependencies are
         * unique within a single POM. Upon multiple declarations, 2.x just kept the last one but retained the order of
         * the first occurrence. So when we're in lenient/compat mode, we have to deal with such broken POMs and mimic

                .collect(Collectors.toList());
    }

    private Map<String, Lifecycle> lookupLifecycles() {
        // TODO: Remove the following code when maven-compat is gone
        // This code is here to ensure maven-compat's EmptyLifecycleExecutor keeps on working.
        if (lookup == null) {
            return customLifecycles != null ? customLifecycles : new HashMap<>();
        }

~~ specific language governing permissions and limitations
~~ under the License.

 -----
 Introduction
 -----
 Hervé Boutemy
 -----
 2016-05-29
 -----

Maven Compat

 Maven2 classes maintained as compatibility layer for plugins that need to keep Maven2 compatibility.

 Plugins should avoid these classes and be updated to use only Maven3 dependencies (and require Maven3): see

    <module>maven-reporting-api</module>
    <module>maven-project-builder</module>
    <module>maven-mercury</module>
    <module>maven-embedder</module>
    <module>maven-toolchain</module>
    <module>maven-compat</module>
    <module>maven-repository</module>
    <module>maven-repository-mercury</module>
  </modules>
  <!--start-->
  <dependencies>
    <dependency>
      <groupId>junit</groupId>

    <module>maven-reporting-api</module>
    <module>maven-project-builder</module>
    <module>maven-mercury</module>
    <module>maven-embedder</module>
    <module>maven-toolchain</module>
    <module>maven-compat</module>
    <module>maven-repository</module>
    <module>maven-repository-mercury</module>
  </modules>
  <!--start-->
  <dependencies>
    <dependency>
      <groupId>junit</groupId>

  <parent>
    <groupId>org.apache.maven</groupId>
    <artifactId>maven</artifactId>
    <version>4.0.0-beta-1-SNAPSHOT</version>
  </parent>

  <artifactId>maven-compat</artifactId>

  <name>Maven Compat (deprecated)</name>
  <description>Deprecated Maven2 classes maintained as compatibility layer.</description>

  <dependencies>
    <dependency>
      <groupId>org.apache.maven</groupId>

import org.apache.maven.bridge.MavenRepositorySystem;
import org.apache.maven.plugin.LegacySupport;
import org.apache.maven.project.ProjectBuilder;

/**
 * This realizes the metadata source via the default hint to provide backward-compat with Maven 2.x whose Plexus version
 * registered component descriptors twice: once keyed by role+roleHint and once keyed by role only. This effectively

    <maven.site.path>ref/4-LATEST/${project.artifactId}</maven.site.path>
  </properties>

  <dependencyManagement>
    <!-- Not included:
         - apache-maven, as it delivers the binaries
         - maven-compat, only used by apache-maven distributions to support older releases
         - maven-slf4j-provider, only used by apache-maven distributions
         - maven-wrapper, only used by apache-maven-wrapper distributions -->

    }

    public MavenProject getTopLevelProject() {
        return topLevelProject;
    }

    public MavenExecutionResult getResult() {
        return result;
    }

    // Backward compat

    /**
     * Returns the plugin context for given key ({@link PluginDescriptor#getPluginLookupKey()} and
     * {@link MavenProject}, never returns {@code null} as if context not present, creates it.
     *

import org.eclipse.aether.RepositorySystemSession;
import org.eclipse.aether.artifact.Artifact;
import org.eclipse.aether.resolution.ArtifactDescriptorResult;

/**
 * Detects Maven3 plugins using maven-compat Maven2 compatibility layer.
 *
 * @since 3.9.3
 */
@Singleton
@Named
class Maven3CompatDependenciesValidator extends AbstractMavenPluginDependenciesValidator {

    @Inject