List<String> tgt = target.getRoles();
            List<String> merged = new ArrayList<>(tgt.size() + src.size());
            merged.addAll(tgt);
            merged.addAll(src);
            target.setRoles(merged);
        }
    }

    protected void mergeContributor_Properties(
            Contributor target, Contributor source, boolean sourceDominant, Map<Object, Object> context) {