}
        }

        /*
         * 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<>();
        }

    <T> void set(@Nonnull Key<T> key, @Nullable T value);

    /**
     * Associates the specified session data with the given key if the key is currently mapped to the given value. This
     * method provides an atomic compare-and-update of some key's value.
     *
     * @param key the key under which to store the session data, must not be {@code null}
     * @param oldValue the expected data currently associated with the key, may be {@code null}

    <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>

        assertEquals(0, c2.compareTo(c1), "expected " + v2 + " == " + v1);
    }

    private void checkVersionsArrayEqual(String[] array) {
        // compare against each other (including itself)
        for (int i = 0; i < array.length; ++i)
            for (int j = i; j < array.length; ++j) checkVersionsEqual(array[i], array[j]);
    }

  <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

        assertEquals(p.getRepositories().size(), clone.getRepositories().size());
        // TODO deep compare the lists
        assertEquals(
                p.getPluginRepositories().size(), clone.getPluginRepositories().size());
        // TODO deep compare the lists
    }

            //                        new Comparator<MetadataGraphEdge>()
            //                        {
            //                            public int compare( MetadataGraphEdge e1
            //                                              , MetadataGraphEdge e2
            //                                              )
            //                            {