I don't think will work. I tried that and the result wasn't an array of Cheerio objects....

Assuming it did work, I'm curious how it is more efficient. Wouldn't having to create a new functional context for each key in `this` be more costly than just creating one new context with the third parameter to `_.map`? Wouldn't that just push more function calls onto the stack?

I also feel like that terseness would reduce readability as well.