/**
  * @see EPSInterface::isSessionActive()
  */
 public function isSessionActive($sessionId, $refreshSession)
 {
     try {
         $isSessionActiveSdtClass = new stdClass();
         $isSessionActiveSdtClass->sessionId = $sessionId;
         $isSessionActiveSdtClass->refreshSession = $refreshSession;
         $response = parent::isSessionActive($isSessionActiveSdtClass);
         if (isset($response->return)) {
             $isSessionActiveFlag = $response->return;
         } else {
             $isSessionActiveFlag = false;
         }
         return $isSessionActiveFlag;
     } catch (SoapFault $sf) {
         throw new ServerException($sf);
     }
 }