PyEval_InitThreads in Python 3: How/when to call it? (the saga continues ad nauseam)

Question

Basically there seems to be massive confusion/ambiguity over when exactly PyEval_InitThreads() is supposed to be called, and what accompanying API

Answer 1

You don't need to call that in your extension modules. That's for initializing the interpreter which has already been done if your C-API extension module is being imported. This interface is to be used by embedding applications.

When is PyEval_InitThreads meant to be called?