So, as MDN (Mozilla Developer Network) says, Function.caller is not only deprecated, but removed from the Relevant Web Standards.
But, this isn't good for me, as I want to know what function is calling a function I have.

I have a set of private variables, and I only want "friend functions" to see those variables without having to return every function from another function. (Also because these private variables are user-defined, and thus can't be predicted, or written in advance.)

So, I was wondering, does modern JS provide anything similar to Function.caller?