public function start()
    {

        // we need the session to be started
        if ($this->isStarted()) {
            return;
        }

        // create a new cookie with the session values
        $cookie = new HttpCookie(
            $this->getName(),
            $this->getId(),
            $this->getLifetime(),
            $this->getMaximumAge(),
            $this->getDomain(),
            $this->getPath(),
            $this->isSecure(),
            $this->isHttpOnly()
        );

        // start the session and set the started flag
        $this->getSession()->start();

        // add the cookie to the response
        $this->getRequest()->setRequestedSessionId($this->getId());
        $this->getResponse()->addCookie($cookie);
    }