/**
* Garbage collect stale sessions from the backend.
* This method should only be called internally by PHP via
* session_set_save_handler().
*
* @param integer $maxlifetime The maximum age of a session.
*
* @return boolean True on success, false otherwise.
*/
public function gc($maxlifetime = 300)
{
return $this->_storage->gc($maxlifetime);
}