`value` might be a length other than 3? That is very unclear from the code here -- I can see that tripping up people who want to modify this code in the future. Can you add a comment about that in the code? Also, if `value` is guaranteed to be no *more* than 3, then it might make sense to create another array of length exactly 3, like this:
```js
// value might have fewer than 3 values, so we create a copy that always has 3 values
var proper_length = [null, null, null];
// populate proper_length from value
_.each(value, function(v, i) {proper_length[i] = v; });
// process proper_length
_.map(proper_length, function() { ...
```