public function export_csv()
{
$c_id = Request::get_c_id();
$session_id = Request::get_session_id();
$course = (object) array();
$course->c_id = $c_id;
$course->session_id = $session_id;
$descriptions = CourseDescription::repository()->find_by_course($course);
$writer = new CsvWriter();
$writer->add($descriptions);
$path = $writer->get_path();
\DocumentManager::file_send_for_download($path, true, get_lang('CourseDescriptions') . '.csv');
}
