/**
* Returns the response's time-to-live in seconds.
*
* It returns null when no freshness information is present in the response.
*
* When the responses TTL is <= 0, the response may not be served from cache without first
* revalidating with the origin.
*
* @return int|null The TTL in seconds
*
* @api
*/
public function getTtl()
{
return parent::getTtl();
}
