static <A extends Concept> LPair<A, S> findBackRefsWithFieldNames(Concept c, Class<A> type) {
  new LPair<A, S> l;
  if (c != null && c.backRefs != null) for (Concept.Ref r : cloneList(c.backRefs))
    if (instanceOf(r.concept(), type))
      l.add(pair((A) r.concept(), fieldNameForConceptLink(r.concept(), c)));
  ret l;
}