RegenerateId() - Regenerate the session id.
RegisterValidator() - register a validator that will attempt to validate this session for every future request
RememberMe() - Send the remember me cookie, which will (on next request) force the session to resend the session cookie that will expire after a number of seconds in the future (not when the browser closes) Seconds are determined by self::$_remember_me_seconds.
RemoveInstance() - Remove the instance.