Security class in Codeigniter

I'm trying to use the Security class in Codeigniter 2.0.2 but I cant seem to find the class to load. Is it hidden somewhere?

Security Librar开发者_StackOverflow中文版y as shown in CI user guide:

http://codeigniter.com/user_guide/libraries/security.html

Tried searching /system/libraries but it is not there...

Trying to load the security class with $this->load->library('security'); gives me an error:

Unable to load the requested class: security

It is in helper according to codeigniter user guide

try

$this->load->helper('security');