Scope of loader class in Codeigniter
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I am confused about what is the scope of loader class. I mean we can use $this->load->library('library_name') to load library. But when it comes to multi-level inheritance, it is not working as expected.

For eg. I have multi-level in inheritance in my project.

'Mysite' controller that extends 'CI_Controller' class.
'Parent' controller that extends 'Mysite' class/controller.
'Child' controller that extends 'Parent' controller.

In Child class if I use, $this->load->library('library_name'), it is not working, and throwing the error that undefined variable.

Can anyone please tell why this behavior? Also possible solution for this problem. 

Thanks.   