static function publish_courses($courses)
{
foreach ($courses as $course_id) {
$course_array = array($course_id);
if (JoomdleHelperShop::is_course_on_sell($course_id)) {
JoomdleHelperShop::dont_sell_courses($course_array);
} else {
JoomdleHelperShop::sell_courses($course_array);
}
}
}