Hi!
PHPUnit 8 changed e.g. ` function setUp(){}` to ` function setUp():
void{} ` and a lot of people did not like being forced to do the same on
their `setUp()`.The issue is not PHPUnit adding `void`, but PHP forcing `void` even when it's not necessary. If PHPUnit wants to use void but inheritors don't want to, it should just be possible. "probably a bad idea" is opinionated, in reality there is no provable reason to disallow it, from a pure type-theory standpoint.
