/**
  * Finally this method does the lookup for the passed resource identifier
  * using the also passed connection.
  *
  * @param \TechDivision\Naming\ResourceIdentifier             $resourceIdentifier The identifier for the requested bean
  * @param \TechDivision\PersistenceContainerClient\Connection $connection         The connection we use for loading the bean
  * @param string                                              $sessionId          The session-ID, necessary for lookup stateful session beans
  *
  * @return object The been proxy instance
  */
 protected function doLookup(ResourceIdentifier $resourceIdentifier, Connection $connection, $sessionId = null)
 {
     // initialize the session
     $session = $connection->createContextSession();
     // check if we've a HTTP session-ID
     if ($sessionId == null && $this->getServletRequest() && ($servletSession = $this->getServletRequest()->getSession())) {
         $sessionId = $servletSession->getId();
         // if yes, use it for connecting to the stateful session bean
     } elseif ($sessionId == null) {
         $sessionId = Uuid::uuid4()->__toString();
         // simulate a unique session-ID
     } else {
         // do nothing, because a session-ID has been passed
     }
     // set the HTTP session-ID
     $session->setSessionId($sessionId);
     // load the class name from the resource identifier => that is the path information
     $className = $resourceIdentifier->getClassName();
     // lookup and return the requested remote bean instance
     return $session->createInitialContext()->lookup($className);
 }