final public function validation($data, $files) {
        $errors = parent::validation($data, $files);
        if (!isset($errors['name'])) {
            $config = cache_config::instance();
            if (in_array($data['name'], array_keys($config->get_locks()))) {
                $errors['name'] = get_string('locknamenotunique', 'cache');
            }
        }
        $errors = $this->plugin_validation($data, $files, $errors);
        return $errors;
    }