public function id()
    {
        // just return any string since the Cookie storage has no idea.
        if ($this instanceof \Pimf\Session\Storages\Cookie) {
            return Character::random(40);
        }

        // we'll find an random ID here.
        do {
            $session = $this->load($key = Character::random(40));
        } while ($session !== null);

        return $key;
    }