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,
));
}