Load Libraries

**New to CI**

I have read the documentation and the Practice CodeIgniter 3.

I can not seem to figure out how to load my own library in 'application/libraries/TestLib'.

Tried :

PHP Code:

$this->load->library('TestLib'); 


and

PHP Code:

$testLib = new App\Libraries\TestLib(); 


I've been looking all over but haven't seemed to figure out why it is not loading.

CodeIgniter-3.1.6