/**
     * Performs an authentication attempt
     *
     * @throws Zend_Auth_Adapter_Exception If authentication cannot be performed
     * @return Zend_Auth_Result
     */
    public function authenticate()
    {
        // get existing or new session
        $session = $this->getSession();

        // see if the session object has been implemented as a resource yet,
        // if not it is becase the user hasn't logged in yet. To log in, a
        // session resource must be created by using a post request to it
        require_once 'models/Handler/Session.php';
        $sessionHandler = new Default_Model_Handler_Session($session);
        if (null === $sessionHandler->get(array('id' => 1))) {
            // no session resource yet, create one as an anonymous/default user
            $sessionHandler->post(array());

            // this gets them in into the system, at which point if the user
            // is in fact themselves posting to the session resource with their
            // credentials, this created session will be forgotten and they
            // will continue on as their proper identity
        }

        require_once 'Zend/Auth/Result.php';
        return new Zend_Auth_Result(Zend_Auth_Result::SUCCESS, $session->identity);
    }