// TODO: run dbBot()

sclass ConceptsLoadedOnDemand {
  Map<S, Concepts> loaded; // key = just the case ID. value can be null in case of error
  Lock lock = lock();
  
  Concepts get(S caseID) { ret conceptsForCase(caseID); }
  
  Concepts conceptsForCase(S caseID) {
    lock lock;
    assertNempty(+caseID);
    
    if (loaded.containsKey(caseID))
      ret assertNempty("Concepts load error", loaded.get(caseID));

    Concepts c = new Concepts(getDBProgramID() + "/" + caseID);
    loaded.put(caseID, c);
    ret c;
  }
}