title: Differentiate session timeout in codeigniter
body: <p>Is is possible to have two user data to have different timeout/expiry time? Let say first data "param_1" expired in 1 day and "param_2" expired in a month. How to do that with CI session library. Something that might be like this</p>
  
  <pre><code>$this-&gt;session-&gt;set_userdata('param_1', 86400);  // seconds in a day
  $this-&gt;session-&gt;set_userdata('param_2', 2592000); // seconds in a month
  </code></pre>