code: public String getRelationship() {
          String prefixRel = RELS_EXT.uri;
          if (predicate != null && predicate.startsWith(prefixRel)) {
              String rel = "rel:" + predicate.substring(prefixRel.length());
              return rel;
          }
          String prefixModel = MODEL.uri;
          if (predicate != null && predicate.startsWith(prefixModel)) {
              String rel =
                      "fedora-model:" + predicate.substring(prefixModel.length());
              return rel;
          }
          return predicate;
      }
docs: TODO: Consider getting rid of this method