Model.Builder builder, Model target, Model source, boolean sourceDominant, Map<Object, Object> context) {
        // don't merge
    }

    @Override
    protected void mergeModel_Developers(
            Model.Builder builder, Model target, Model source, boolean sourceDominant, Map<Object, Object> context) {
        // don't merge
    }

    @Override
    protected void mergeModel_Licenses(

        if (target.getLicenses().isEmpty()) {
            target.setLicenses(new ArrayList<>(source.getLicenses()));
        }
    }

    @Override
    protected void mergeModel_Developers(
            Model target, Model source, boolean sourceDominant, Map<Object, Object> context) {
        if (target.getDevelopers().isEmpty()) {
            target.setDevelopers(new ArrayList<>(source.getDevelopers()));

        mergeModel_Licenses(target, source, sourceDominant, context);
        mergeModel_MailingLists(target, source, sourceDominant, context);
        mergeModel_Developers(target, source, sourceDominant, context);
        mergeModel_Contributors(target, source, sourceDominant, context);
        mergeModel_IssueManagement(target, source, sourceDominant, context);