@Deprecated(since = "4.0.0")
public class MavenToolchainMerger {

    public void merge(PersistedToolchains dominant, PersistedToolchains recessive, String recessiveSourceLevel) {
        if (dominant == null || recessive == null) {
            return;
        }

        recessive.setSourceLevel(recessiveSourceLevel);

        shallowMerge(dominant.getToolchains(), recessive.getToolchains(), recessiveSourceLevel);
    }

                }
            }
        }

        if (dominant.getLocalRepository() == null
                || dominant.getLocalRepository().isEmpty()) {
            dominant.setLocalRepository(recessive.getLocalRepository());
        }

        shallowMergeById(dominant.getMirrors(), recessive.getMirrors(), recessiveSourceLevel);
        shallowMergeById(dominant.getServers(), recessive.getServers(), recessiveSourceLevel);

        try (InputStream isDominant = MavenToolchainMergerTest.class.getResourceAsStream("toolchains-jdks.xml");
                InputStream isRecessive = MavenToolchainMergerTest.class.getResourceAsStream("toolchains-jdks.xml")) {
            PersistedToolchains dominant = read(isDominant);
            PersistedToolchains recessive = read(isRecessive);
            assertEquals(2, dominant.getToolchains().size());

        return XmlService.merge(this, source, childMergeOverride);
    }

    /**
     * Merge recessive into dominant and return either {@code dominant}
     * with merged information or a clone of {@code recessive} if
     * {@code dominant} is {@code null}.
     *
     * @param dominant the node
     * @param recessive if {@code null}, nothing will happen
     * @return the merged node
     *

    @Nullable
    public static XmlNode merge(XmlNode dominant, XmlNode recessive) {
        return merge(dominant, recessive, null);
    }

    /**
     * Merges two XML nodes.
     */
    @Nullable
    public static XmlNode merge(
            @Nullable XmlNode dominant, @Nullable XmlNode recessive, @Nullable Boolean childMergeOverride) {
        return getService().doMerge(dominant, recessive, childMergeOverride);
    }

        // don't allow construction.
    }

    /**
     * @param dominant
     * @param recessive
     * @param recessiveSourceLevel
     */
    public static void merge(Settings dominant, Settings recessive, String recessiveSourceLevel) {
        if (dominant != null && recessive != null) {
            dominant.delegate = SettingsUtilsV4.merge(dominant.getDelegate(), recessive.getDelegate());
        }
    }

    /**

            List<Repository> dominant, recessive;
            if (sourceDominant) {
                dominant = src;
                recessive = tgt;
            } else {
                dominant = tgt;
                recessive = src;
            }

            for (Repository element : dominant) {
                Object key = getRepositoryKey(element);

        Settings dominant = Settings.newBuilder()
                .pluginGroups(Arrays.asList("org.apache.maven.plugins", "org.codehaus.modello"))
                .build();

        Settings recessive = Settings.newBuilder()
                .pluginGroups(Arrays.asList("org.codehaus.plexus"))
                .build();

        Settings merged = SettingsUtilsV4.merge(dominant, recessive);

    }

    private Properties toProperties(Map<String, String> dominant, Map<String, String> recessive) {
        Properties props = new Properties();
        if (recessive != null) {
            props.putAll(recessive);
        }
        if (dominant != null) {
            props.putAll(dominant);
        }
        return props;
    }

    private Artifact getRelocation(

    @Nonnull
    RemoteRepository createRemote(@Nonnull Repository repository);

    @Nonnull
    List<RemoteRepository> aggregate(
            @Nonnull Session session,
            @Nonnull List<RemoteRepository> dominant,
            @Nonnull List<RemoteRepository> recessive,
            boolean processRecessive);