anchor.diff:  (defclass renderer ()
     ((buffers :accessor buffers :initform nil)
      (bundles :accessor bundles :initform nil)
  -   (new-bundles :accessor new-bundles :initform nil)))
  +   (new-bundles :accessor new-bundles :initform nil)
  +   (current-state :accessor current-state :initform nil)))
   
   ;;; A simple reference counting protocol for objects that should do some
   ;;; cleanup e.g., release OpenGL resources, when they are no longer used.
  
positive.code: 
  (defgeneric bind-state (renderer state))
  
  (defmethod bind-state ((renderer renderer) (state graphics-state))
    )
  
  (defun draw-render-groups (renderer)
    (upload-bundles renderer)
  
negative.code:   ((descriptor :accessor descriptor :initarg :descriptor)
     (local-storage :accessor local-storage)
     (strategy-data :accessor strategy-data)))
  
  
  (defun has-valid-strategy-p (uset)
    (with-slots (descriptor strategy-data)
  