Sorry, I may have read too fast :). I personally don't see a big improvement visually speaking in the two versions:

```ruby
[ dom_class(record, prefix), options[:class] ]
[dom_class(record, prefix), options[:class]]

[ status, headers, [body] ]
[status, headers, [body]]
```

But I'm not going to block your change because of that, because it's more a personal preference I guess. I'm merging as is, thank you.