private static function module_setup_exists($module_setup_classname)
 {
     return ClassLoader::is_class_registered_and_valid($module_setup_classname);
 }
 private function check_provider($provider_id)
 {
     $provider_classname = $this->compute_provider_classname($provider_id);
     return ClassLoader::is_class_registered_and_valid($provider_classname);
 }