anchor.diff:            (my-circle (make-instance 'circle))
             (my-color (make-instance 'color)))
         (get-kind my-shape)
  -      (assert-equal ____ *last-kind-accessor*)
  +      (assert-equal :shape *last-kind-accessor*)
         (get-kind my-circle)
  -      (assert-equal ____ *last-kind-accessor*)
  +      (assert-equal :circle *last-kind-accessor*)
         (get-kind my-color)
  -      (assert-equal ____ *last-kind-accessor*)
  +      (assert-equal :color *last-kind-accessor*)
         (get-kind my-colored-circle)
  -      (assert-equal ____ *last-kind-accessor*)
  +      (assert-equal :color *last-kind-accessor*)
         (get-kind my-circled-color)
  -      (assert-equal ____ *last-kind-accessor*)))
  +      (assert-equal :circle *last-kind-accessor*)))
   
   
   ;; Todo: consider adding :before and :after method control instructions.
  
positive.code: (define-test test-access-counter
      (let ((x (make-instance 'value-with-access-counter)))
        ; check that no one has ever looked at the x value yet.
        (assert-equal ____ (how-many-value-queries x))
        ; check that the default value is zero.
        (assert-equal ___ (get-value x))
        ; now that we've looked at it, there is a single access.
        (assert-equal ___ (how-many-value-queries x))
        ; check that we can set and read the value
        (set-value 33 x)
        (assert-equal 33 (get-value x))
        (assert-equal ___ (how-many-value-queries x))))
  
  
  ; countdowner has a value which goes down every time you look at it
  
negative.code: (define-test test-clos-getters-and-setters
      (let ((ship-1 (make-instance 'spaceship)))
        (set-color :orange ship-1)
        (assert-equal :orange (get-color ship-1))
        (set-speed 1000 ship-1)
        (assert-equal 1000 (get-speed ship-1))))
  
  ;; CLOS also provides functionality to create accessors
  ;; to object data.
  