sclass ConceptShadow {
  Map map;
  bool refsConvertedToIDs;
  
  *(Concept c) {
    map = conceptShadow_rawMap(c);
    MetaTransformer tf = metaTransformer_collectionAndMap();
    // dereference concept refs
    map = toMinimalMap((Map) tf.transform(lambda1 derefRefOrNull, map);
  }
  
  void convertRefsToIDs {
    if (refsConvertedToIDs) ret;
    set refsConvertedToIDs;
    MetaTransformer tf = metaTransformer_collectionAndMap();
    map = toMinimalMap(mapValues(map, o -> tf.transform(lambda1 conceptToIDObj_gen, o)));
  }
  
  toString { ret "ConceptShadow " + stringIf(refsConvertedToIDs, "[converted] ") + map; }
  
  O get(O key) { ret mapGet(map, key); }
}