anchor.diff:    (:documentation
      "Mixin class for layout panes, which want to behave like a HBOX/VBOX."))
   
  -;; First we need to make sure that the list of clients and the list of
  -;; children agree with each other.
  +;;; First we need to make sure that the list of clients and the list
  +;;; of children agree with each other.
   
   (defmethod sheet-adopt-child :after ((sheet box-layout-mixin) child)
     ;; When the child is already known in the client list we add no new
  
positive.code:   ;; finally do a re-layout.
    (change-space-requirements pane) )
  
  ;;;;
  
  (eval-when (:compile-toplevel :load-toplevel :execute)
    (defun make-box-macro-contents (contents)
      (loop
  
negative.code: (defmethod compose-space ((pane table-pane) &key width height)
    (declare (ignore width height))
    (with-slots (array x-spacing y-spacing) pane
      ;; ---v our problem is here.
      ;; Which problem? --GB
      (let ((rsrs (loop for i from 0 below (array-dimension array 0) 
                      collect (table-pane-row-space-requirement pane i)))
            (csrs (loop for j from 0 below (array-dimension array 1) 
  