svoid deleteConcept_sync(long id) {
  deleteConcept_sync(db_mainConcepts(), id);
}

svoid deleteConcept_sync(Concepts concepts, long id) {
  withDBLock(concepts, r { concepts.deleteConcept(id) });
}

static void deleteConcept_sync(Concept c) {
  if (c != null) withDBLock(c._concepts, r { c.delete() });
}

static void deleteConcept_sync(Concept.Ref ref) {
  if (ref != null) deleteConcept_sync(ref.get());
}