/**
  * Get URL for external login
  *
  * @param array $returnQueryVars Query variables that should be added to the return URL
  * @return string
  */
 public function getLoginUrl(array $returnQueryVars = array())
 {
     if ($this->isExternal()) {
         return $this->authController->getLoginUrl($returnQueryVars);
     }
     return false;
 }