How does should_nest work?

[knownasnaffy]

I see that the should_nest config function provides a channel integer to work with, but I'm not sure how to use that. I wanted to block instances started with sudo to not nest.

As I often find myself edit configurations under /etc/ with sudo -E -s nvim and passing root permissions is not really possible (polkit might be an approach but that's a hole too deep for me to want to go in), I wanted to know about this option

[knownasnaffy]

I actually found a better answer for my situation, to use lambdalisue/vim-suda. But i'd still like to know about more about should_nest just to satisfy my curiosity.