title: Set Session Expiration Time Manually-CodeIgniter
body: <p>How can I set session expiration time dynamically in codeigniter?</p>
  
  <p>For example, if a user logs in and has the role of <code>admin</code>, the expiration time should be longer than if a user logs in who does not have an <code>admin</code> role.</p>
  
  <p>Thanks.</p>