return merge(dominant, recessive, null);
    }

    @Nullable
    static XmlNode merge(
            @Nullable XmlNode dominant, @Nullable XmlNode recessive, @Nullable Boolean childMergeOverride) {
        if (recessive == null) {
            return dominant;
        }
        if (dominant == null) {
            return recessive;
        }

    @Override
    protected void merge(Metadata recessive) {
        Versioning original = metadata.getVersioning();

        Versioning.Builder versioning = Versioning.newBuilder(original);
        versioning.lastUpdated(fmt.format(timestamp));

        if (recessive.getVersioning() != null) {
            if (original.getLatest() == null) {
                versioning.latest(recessive.getVersioning().getLatest());
            }

                        .name(pluginInfo.name)
                        .build()))
                .build();
    }

    @Override
    protected void merge(Metadata recessive) {
        List<Plugin> recessivePlugins = recessive.getPlugins();
        List<Plugin> plugins = metadata.getPlugins();
        if (!recessivePlugins.isEmpty() || !plugins.isEmpty()) {

        metadata = metadata.withVersioning(metadata.getVersioning().withSnapshotVersions(versions.values()));

        // just carry-on as-is
        if (recessive.getPlugins() != null && !recessive.getPlugins().isEmpty()) {
            metadata = metadata.withPlugins(new ArrayList<>(recessive.getPlugins()));
        }
    }

    private static int getBuildNumber(Metadata metadata) {
        int number = 0;

        metadata = metadata.withVersioning(metadata.getVersioning().withSnapshotVersions(versions.values()));

        // just carry-on as-is
        if (recessive.getPlugins() != null && !recessive.getPlugins().isEmpty()) {
            metadata = metadata.withPlugins(new ArrayList<>(recessive.getPlugins()));
        }

        artifacts.clear();
    }

    private String getKey(String classifier, String extension) {

    }

    /**
     * @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());
        }
    }

    /**
     * @param modelProfile

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

            for (Repository element : dominant) {

                internalSession.getSession(),
                internalSession.toRepositories(nonNull(dominant, "dominant")),
                internalSession.toRepositories(nonNull(recessive, "recessive")),
                processRecessive);
        return repos.stream()
                .<RemoteRepository>map(DefaultRemoteRepository::new)
                .toList();
    }

        Metadata recessive = read(existing);

        merge(recessive);

        write(result, metadata);

        merged = true;
    }

    @Override
    public boolean isMerged() {
        return merged;
    }

    protected abstract void merge(Metadata recessive);

    static Metadata read(Path metadataPath) throws RepositoryException {

                .build();

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

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

        List<String> pluginGroups = merged.getPluginGroups();

        assertNotNull(pluginGroups);