What are the CI4 ways to use Database and Library in a Helper?

I need to use a database model and library in my helper. Also need to use a library. In CI 3 I used to do it like following:

PHP Code:

$CI =& get_instance();
$CI->load->model('a_modal');
$CI->load->library('a_library'); 


Now I am little bit confused about the CI 4. What are the ways to do this? What is the CodeIgniter way to do it?

Thanks in advance.

"Who thinks in code"
Perfectly describes who I am
mbparvez.me