anchor.diff:       (with-slots (major-spacing) box
          (let* ((content-srs (mapcar #'(lambda (c) (xically-content-sr*** box c major))
                                      (box-layout-mixin-clients box)))
  -              (allot       (mapcar #'ceiling (mapcar #'space-requirement-major content-srs)))
  +              (allot       (mapcar #'space-requirement-major content-srs))
                 (wanted      (reduce #'+ allot))
                 (excess      (- major wanted
                                 (* (1- (length children)) major-spacing))))
  
positive.code: 
        ;; It's not a bug, it's a feature. This requires further thought. -Hefner
        (move-sheet child
                    (round (- (if (> (+ horizontal-scroll viewport-width)
                                     child-width)
                                  (- child-width viewport-width)
                                  horizontal-scroll)))
                    (round (- (if (> (+ vertical-scroll viewport-height)
                                     child-height)
                                  (- child-height viewport-height)
                                  vertical-scroll))))
        (scroller-pane/update-scroll-bars (sheet-parent pane)))))
  
  ;;; SCROLLER PANE
  
negative.code: 
  (defmethod scroll-extent ((pane basic-pane) x y)
    (when (pane-viewport pane)
      (move-sheet pane (- x) (- y))
      (when (pane-scroller pane)
        (scroller-pane/update-scroll-bars (pane-scroller pane)))))
  
  