protected function doSave($id, $data, $lifeTime = 0)
{
$data = serialize($data);
if ($lifeTime > 0) {
$response = $this->client->setex($id, $lifeTime, $data);
} else {
$response = $this->client->set($id, $data);
}
return $response === true || $response == 'OK';
}