public function session($name, Course $course, $status = 0)
 {
     $now = new \DateTime();
     $session = new CourseSession();
     $session->setName($name);
     $session->setCourse($course);
     $session->setCreationDate($now);
     $session->setSessionStatus($status);
     $this->om->persist($session);
     return $session;
 }