public function saveCertificateUser(JosCertificateUser $certificate_user)
 {
     $data = array('certificate_id' => $certificate_user->getCertificateId(), 'user_id' => $certificate_user->getUserId(), 'note' => $certificate_user->getNote(), 'level' => $certificate_user->getLevel());
     $this->tableGateway->insert($data);
 }