anchor.diff:  		     &rest args
   		     &key (filled t) (closed t)
   			  ink clipping-region transformation line-style line-thickness
  -			  line-unit line-dashes line-cap-shape)
  -  (declare (ignore ink clipping-region transformation line-style line-thickness
  -		   line-unit line-dashes line-cap-shape))
  +			  line-unit line-dashes line-joint-shape line-cap-shape)
  +  (declare (ignore ink clipping-region transformation line-style line-thickness
  +		   line-unit line-dashes line-joint-shape line-cap-shape))
     (with-medium-options (sheet args)
       (loop for point in point-seq
   	  nconcing (multiple-value-bind (x y) (point-position point)
  
positive.code: 			&rest args
  			&key (filled t)
  			     ink clipping-region transformation line-style line-thickness
  			     line-unit line-dashes line-cap-shape)
    (declare (ignore ink clipping-region transformation line-style line-thickness
  		   line-unit line-dashes line-cap-shape))
    (with-medium-options (sheet args)
      (medium-draw-rectangle* medium x1 y1 x2 y2 filled)))
  
  
negative.code: ;;; -*- Mode: Lisp; Package: CLIM-INTERNALS -*-
  
  ;;;  (c) copyright 1998,1999,2000 by Michael McDonald (mikemac@mikemac.com)
  ;;;  (c) copyright 2001 by Arnaud Rouanet (rouanet@emi.u-bordeaux.fr)
  
  ;;; This library is free software; you can redistribute it and/or
  ;;; modify it under the terms of the GNU Library General Public
  