[racket] Overriding methods in Racket classes

Sorry -- typo in my code, my last email should read:

OK using define-local-member-name works, see case 1 below, but it
 seems it would be much simpler if there was a form define/inheritable
 which made the method accessable within the class body where it was
 defined and in the sub-class bodies only. (see case 2 below)
 i.e. no wrapping in a let that returned multiple values etc.

 Is there some reason there isn't such a form define/inheritable ?

 ===================================
 Case 1 (using define-local-member-name)
 =================================
 #lang racket
 (define-values (fish% picky-fish%)
   (let ()
     (define-local-member-name grow)
 (define fish% (class object%
  (init size)                ; initialization argument

   (define current-size size) ; field

   (super-new)                ; superclass initialization

   (define/public (get-size)
     current-size)

   (define/public (grow amt)
     (set! current-size (+ amt current-size)))

   (define/public (eat other-fish)
    (grow (send other-fish get-size)))))

 (define picky-fish% (class fish% (super-new)
                       (define/override (grow amt)

                         (super grow (* 3/4 amt)))))
    (values fish% picky-fish%)))

 (define joe-the-minnow (new fish% [size 2]))
 (define bud-the-minnow (new fish% [size 2]))
 (define big-al-the-pike (new fish% [size 10]))
 (define picky-selma (new picky-fish% [size 5]))

 (send picky-selma eat joe-the-minnow)
 (send picky-selma get-size)

 ;;this now correctly fails
 ;(send bud-the-minnow grow 5)
 ====================================
 (Case 2 using a hypothetical define/inheritable)
 ====================================
 #lang racket

 (define fish% (class object%
   (init size)

   (define current-size size)

   (super-new)

   (define/public (get-size)
     current-size)

   (define/inheritable (grow amt)  ;;;hypothetical define/inheritable
     (set! current-size (+ amt current-size)))

  (define/public (eat other-fish)
     (grow (send other-fish get-size)))))

 (define picky-fish% (class fish% (super-new)
                       (define/override (grow amt)

                         (super grow (* 3/4 amt)))))

(define joe-the-minnow (new fish% [size 2]))
 (define bud-the-minnow (new fish% [size 2]))
 (define big-al-the-pike (new fish% [size 10]))
 (define picky-selma (new picky-fish% [size 5]))

 (send picky-selma eat joe-the-minnow)
 (send picky-selma get-size)

 Thanks,
 Harry Spier