As I see this function, the goal is to check that some setting has the right value, and therefore we should not assume the setting to be a number. It would also do side effects if later we had a new setting using a string, and we use this function, and we won't understand why it doesn't work, before looking at its implementation. That's why I think using isNaN is not the right solution here.

I'll switch to use `arguments`, because we can argue that "undefined" can be a valid thing to check.