public function save_settings(stdClass $data) {
        $this->set_config('maxfilesubmissions', $data->assignsubmission_file_maxfiles);
        $this->set_config('maxsubmissionsizebytes', $data->assignsubmission_file_maxsizebytes);

        if (!empty($data->assignsubmission_file_filetypes)) {
            $this->set_config('filetypeslist', $data->assignsubmission_file_filetypes);
        } else {
            $this->set_config('filetypeslist', '');
        }

        return true;
    }