Templates in CI version 4

Hey guys

First, I'm not sure if 'template' is the technical term for this. In CI version 3, I created a MY_Loader file in the core folder and I used that to load the Header, View, and Footer with just one line of code:

MY_Loader.php


Then inside the controllers I'd use it like this:

Controller


How do I do this with CI 4? So far I've been loading the views for the Header, View, and Footer files individually in each instance, which is not ideal if I want to switch templates (from v1 to v2, for example).