public boolean isIndexed(Class<Object> clazz) {
   return getIndexedClasses().contains(clazz.getName());
 }
 private static URL packageRelativeResource(String resourceName, Class<?> clazz) {
   String directoryPrefix = '/' + clazz.getPackage().getName().replaceAll("\\.", "/") + '/';
   return clazz.getResource(directoryPrefix + resourceName);
 }