anchor.diff:            (draw-text* pane (clime:label-pane-label pane)
                         tx ty)
             ;;;
  -          (when (sheet-children pane)
  +          (when (sheet-child pane)
               (with-drawing-options (pane
                                      :clipping-region
                                      (region-difference
  
positive.code:                                     (make-rectangle* (- tx m0) (- ty a) (+ tx tw m0) (+ ty d))))
                (draw-bordered-rectangle* pane (+ x1 bleft) (+ y1 btop) (- x2 bright) (- y2 bbottom)
                                          :style :groove))))))))
  
  
  (defmethod initialize-instance :after ((pane label-pane) &key contents &allow-other-keys)
    (when contents
      (sheet-adopt-child pane (first contents))))
  
  ;;; GENERIC FUNCTIONS
  
  
negative.code: 
  (defmethod allocate-space ((pane label-pane) width height)
    (multiple-value-bind (right top left bottom) (label-pane-margins pane)
      (alexandria:when-let ((child (sheet-child pane)))
        (multiple-value-bind (x1 y1 x2 y2) (values 0 0 width height)
          (move-sheet child (+ x1 left) (+ y1 top))
          (allocate-space child
  