Config Static Variables Not Working

What is the visibility of $this->config in BaseCOntroller? If set to private, AdminController can't access it. Needs to be at least protected or public.

I am just accessing it using

PHP Code:

$this->config = config('My_config'); 


and then calling its method 

PHP Code:

$this->config::load_values(); 


to populate static variables of the config class.
As per documentation

// Get shared instance with config function
$config = config('Pager');