/**
  * Send quit mail
  *
  * @param integer $a_booking_ids booking ids
  */
 private function sendQuitMail($a_booking_ids)
 {
     $mailer = new ilRoomSharingMailer($this->lng, $this->pool_id);
     $mailer->sendParticipationCancelMail($this->ilUser->getId(), $a_booking_ids);
     $mailer->sendParticipationCancelMailForCreator($this->ilUser->getId(), $a_booking_ids);
 }