mattgreen/nitron — pull request #18 by macfanatic (2012-06-27 15:20:48+00:00)
Title: Allow chaining of order() calls

You couldn't chain order calls before this, b/c the `Array` instance returned from `sortDescriptors` method was an immutable object in Objc, so I now just use a `mutableCopy` of that Array & append the new sort, ie:

```ruby
Task.order(:created_at).order(:title, ascending: false) # orders by both fields, doesn't throw exception now
```