docs: private Map<String, Set<String>> scanForAnnotatedClasses(Set<URL> urls) throws IOException {
          AnnotationDB db = new AnnotationDB();
          db.setScanClassAnnotations(true);
          db.setScanFieldAnnotations(false);
          db.setScanMethodAnnotations(false);
          db.setScanParameterAnnotations(false);
        
          db.scanArchives(urls.toArray(new URL[urls.size()]));
          return db.getAnnotationIndex();
          
      }