Yeah, I went and saw where you assigned it before I posted that comment just to check. The case is that when a subprocess terminates abnormally and it did not terminate from a signal being sent, `isRunning()` will return `true` - and there's usually never a downside to using `== null` because most people use `null` and `undefined` almost interchangeably. There's usually only very subtle differences between them, which you don't really need to know about anyway. `== null` will almost always do what you want it to, there's no point exposing yourself to edge cases you didn't know about.