anchor.diff:      space))
   
   (defmethod allocate-space ((box hbox-pane) width height)
  -  (setf (sheet-region box) (make-bounding-rectangle 0 0 width height))
  +  (set-width-and-height box width height)
     (let ((h-percent (/ width (space-requirement-width (pane-space-requirement box))))
   	(v-percent (/ height (space-requirement-height (pane-space-requirement box))))
   	(x 0))
  
positive.code: 	(y (window-configuration-event-y event))
  	(width (window-configuration-event-width event))
          (height (window-configuration-event-height event)))
      ;; avoid goint into an infinite loop by not using (setf sheet-region)
      (setf (slot-value pane 'transformation)
  	  (make-translation-transformation x y))
      (setf (slot-value pane 'region)
  	  (make-bounding-rectangle 0 0 width height))
      (allocate-space pane width height)))
  
  ;; SHEET 
  
  
negative.code: (defmethod ask-space-children ((composite composite-pane))
    (mapcar #'compose-space (sheet-children composite)))
  
  ;;; FIXME: this one shoud be removed
  (defmethod compute-space ((composite composite-pane))
    (let ((space (make-space-requirement)))
      (loop for child in (sheet-children composite)
  