function fetchData($username, $password, $isChallengeResponse = false)
 {
     $username = ilAuthContainerDatabase::toUsernameWithoutDomain($username);
     $isSuccessful = parent::fetchData($username, $password, $isChallengeResponse);
     if ($this->isObserversEnabled) {
         if ($isSuccessful) {
             $this->loginObserver($username);
         } else {
             $this->failedLoginObserver();
         }
     }
     return $isSuccessful;
 }