please help with sess_expiration

hi

in CI2 i used to set  >>  sess_expiration = 0

The number of seconds you would like the session to last. The default value is 2 hours (7200 seconds). If you would like a non-expiring session set the value to zero: 0

but now in CI 3

The number of seconds you would like the session to last. If you would like a non-expiring session (until browser is closed) set the value to zero: 0


what if i want the session not expired at all ? i want it renewable and non-expiring .

please help me with this