anchor.diff:  (defgeneric graft-units (graft))
   
   (defgeneric text-style-character-width (text-style medium char))
  +;; fall back, where to put this?
  +(defmethod text-style-character-width (text-style medium char)
  +  (text-size medium char :text-style text-style))
   
   (declaim (ftype (function (t t t
                                &key (:filled t) (:ink t) (:clipping-region t) (:transformation t)
  
positive.code: (defgeneric medium-line-style (medium))
  (defgeneric medium-text-style (medium))
  (defgeneric medium-default-text-style (medium))
  
  (defgeneric (setf medium-foreground) (new-value medium))
  (defgeneric (setf medium-background) (new-value medium))
  
negative.code:   (SETF GADGET-MAX-VALUE) (SETF GADGET-MIN-VALUE) (SETF SCROLL-BAR-THUMB-SIZE) 
    SLOT-ACCESSOR-NAME::|CLIM-INTERNALS CLIENT slot READER| DRAW-EDGES-LINES* 
    FORMAT-CHILDREN GADGET-VALUE MAKE-MENU-BAR TABLE-PANE-NUMBER 
  
  ||#