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.

I answered you here, where you previously asked this question.