static <A extends Concept> A nuLike shallowCloneToUnlistedConcept(Class<A> c, O o) {
  if (o == null) null;
  A cc = unlisted(c);
  copyFields(o, cc, conceptFields(c));
  ret cc;
}

static <A extends Concept> A shallowCloneToUnlistedConcept(A o) {
  ret o == null ? null : shallowCloneToUnlistedConcept(getClass(o), o);
}