}
        }

        /*
         * 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}

        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]);
    }

        for (String version : args) {
            ComparableVersion c = new ComparableVersion(version);

            if (prev != null) {
                int compare = prev.compareTo(c);
                System.out.println("   " + prev.toString() + ' ' + ((compare == 0) ? "==" : ((compare < 0) ? "<" : ">"))
                        + ' ' + version);
            }

            System.out.println(

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
            //                                              )
            //                            {

     * <li>{@code repo,repo1} = {@code repo} or {@code repo1},</li>
     * <li>{@code *,!repo1} = everything except {@code repo1}.</li>
     * </ul>
     *
     * @param originalRepository to compare for a match.
     * @param pattern used for match.
     * @return true if the repository is a match to this pattern.
     */
    static boolean matchPattern(ArtifactRepository originalRepository, String pattern) {

    }

    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.
     *