title: how can i use set_userdata in codeigniter4 for adding session data
body: <p>I am migrating codeigniter 2 to codeigniter 4.
  I am facing lot of discrepencies.
  Ex set_userdata. Its not available in codeigniter 4.</p>
  <p>how can i use set_userdata in  codeigniter4 exactly like codeigniter 2.
  Please help</p>