sclass BEAUtils {
  Map<S, Class<? extends BEAObject>> beaClasses = calcBEAClasses();
  
  Map<S, Class<? extends BEAObject>> beaClasses() {
    ret beaClasses if null = calcBEAClasses();
  }
  
  // e.g. "Input" => BInput
  Map<S, Class<? extends BEAObject>> calcBEAClasses() {
    ret ciMapToKeys(c -> dropPrefix("B", shortClassName(c)),
      listMinusItem(BEAObject, myNonAbstractClassesImplementing(BEAObject)));
  }
  
  Class<? extends BEAObject> defaultCustomClass(BEAObject o) {
    ret beaClasses().get(o.type());
  }
  
  <A extends BEAObject> A migrateConceptToClass(Class<A> c, BEAObject in) {
    A out = unlisted(c);
    for (S field : conceptFields(in)) try {
      continue if eq(field, "type");
      cset(out, field, cget(in, field));
      // TODO: check Ref types
    } catch e {
      fail("Can't convert field " + field, e);
    }
    ret out;
  }
  
  BEAObject autoMigrate(BEAObject o) {
    pcall {
      Class<? extends BEAObject> targetClass = defaultCustomClass(o);
      printVars_str(+o, +targetClass);
      if (targetClass != null && targetClass != _getClass(o))
        ret replaceConceptAndUpdateRefs(o, migrateConceptToClass(targetClass, o));
    }
    ret o;
  }
}