anchor.diff:          | AnimatedSprite (resource, celSize, celRun, celCount, stutter, aspects) ->
               evalAnimatedSprite viewType slice history resource celSize celRun celCount stutter aspects time
           | PhysicsShape (label, bodyShape, collisionCategories, collisionMask, aspects) ->
  -            ignore (label, bodyShape, collisionCategories, collisionMask, aspects); failwith "TODO"
  +            ignore (label, bodyShape, collisionCategories, collisionMask, aspects); [] // TODO: implement
           | Composite aspects ->
               evalComposite viewType slice history aspects time
   
  
positive.code:         | Depth _ -> Right aspect
          | Color _ -> Right aspect
          | Mount _ -> Right aspect
          | Emit -> Right aspect
          | Bone -> Right aspect
  
  
negative.code:     | Depth of TweenApplicator * Algorithm * TweenNode list
      | Color of TweenApplicator * Algorithm * Tween4Node list
      | Mount of Content
      | Repeat // TODO
      | Emit // TODO
      | Bone // TODO
  
  