I think you're on the right track with the base class. Maybe we should move all the behaviors to the base class? Then we just need to call them in the view controllers. Make them methods like:

```ruby
def new_collision_behavior(items)
  behavior = UICollisision.alloc.initWithItems(items)
  # other collision method stuff here
  behavior
end
```

Then when we use them in the views with can just assign them in `viewDidLoad`

```ruby
def viewDidLoad
  collision_behaviors = new_collision_behavior([box_one, box_two])
end
```

That way they're all together. The only issue i can foresee is if they differ between views.