Symfony\Component\HttpFoundation\Session::save PHP Method

    public function save()
    {
        if (false === $this->started) {
            $this->start();
        }

        $this->flashes = array_diff_key($this->flashes, $this->oldFlashes);

        $this->storage->write('_symfony2', array(
            'attributes' => $this->attributes,
            'flashes'    => $this->flashes,
            'locale'     => $this->locale,
        ));
    }