public function lookupStatefulSessionBean($sessionId, $className)
    {

        // create a unique SFSB identifier
        $identifier = SessionBeanUtil::createIdentifier($sessionId, $className);

        // load the map with the SFSBs
        $sessionBeans = $this->getStatefulSessionBeans();

        // if the SFSB exists, return it
        if ($sessionBeans->exists($identifier)) {
            return $sessionBeans->get($identifier);
        }
    }