static L<Class> nonAbstractClassesInRealmWithSuperclassShortNamed(Class realm, S base, L<S> candidateClassNames) {
  new L<Class> l;
  S prefix = mainClassNameForClassLoader(realm.getClassLoader()) + "$";
  for (S name : candidateClassNames) pcall {
    Class c = _getClass(realm, prefix + name);
    if (c != null && !isAbstract(c) && hasSuperclassShortNamed(c, base))
      l.add(c);
  }
  ret l;
}