How to overwrite pagination

Hi,
I need to make some changes in pagination and for this copied file
system/libraries/Pagination.php and copied it into
application/core/Pagination.php
and I made changes I need in last file, but these changes were not applied.
Which is the correct way ?

PHP Code:

CI_VERSION:3.1.2  


Thanks!

Move/rename your copy to application/libraries/MY_Pagination.php

See https://www.codeigniter.com/user_guide/g...r-versions