How to setup IMAP in CodeIgniter

How can I setup IMAP in CodeIgniter. For now, I'm using just pure php. But I need to change as CodeIgniter Standard. Please help me. Here is my IMAP Setup with Pure php

// Connect to gmail
                    $hostname = '{imap.gmail.com:993/ssl/novalidate-cert}[Gmail]/All Mail';
                    $username = 'my email';
                    $password = 'my password';