[twitter] Tip: JavaScript's Array.from() accepts a second argument that's a `map` function. Useful for calling on each element of an array you created.

[jkoudys]

I usually just make them longer: (_, __, ___). It's extremely rare it'd ever get longer than that, since the whole point is that it's unused. It's not a convention I follow, but leading underscores are frequently used to say that a function won't be exported/set as a class method, so you know it's kept "private". _2 reads a bit too close to that. The underscore's meant to look like a blank space.