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

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

    @Override
    protected void mergeModel_Profiles(

        if (target.getContributors().isEmpty()) {
            target.setContributors(new ArrayList<>(source.getContributors()));
        }
    }

    @Override
    protected void mergeModel_MailingLists(
            Model target, Model source, boolean sourceDominant, Map<Object, Object> context) {
        if (target.getMailingLists().isEmpty()) {

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