*/
    private static <T extends IdentifiableBase> void shallowMergeById(
            List<T> dominant, List<T> recessive, String recessiveSourceLevel) {
        Map<String, T> dominantById = mapById(dominant);
        final List<T> identifiables = new ArrayList<>(recessive.size());

        for (T identifiable : recessive) {
            if (!dominantById.containsKey(identifiable.getId())) {