anchor.diff:  
   (define-ffi-method ffi-window-set-buffer ((window gtk-window) (buffer gtk-buffer) &key (focus t))
     "Set BROWSER's WINDOW buffer to BUFFER."
  -  (gtk:gtk-container-remove (active-buffer-container window) (gtk-object (active-buffer window)))
  -  (gtk:gtk-box-pack-start (active-buffer-container window) (gtk-object buffer) :expand t :fill t)
  +  (gtk:gtk-container-remove (main-buffer-container window) (gtk-object (active-buffer window)))
  +  (gtk:gtk-box-pack-start (main-buffer-container window) (gtk-object buffer) :expand t :fill t)
     (gtk:gtk-widget-show (gtk-object buffer))
     (when focus
       (gtk:gtk-widget-grab-focus (gtk-object buffer)))
  
positive.code:        (setf active-buffer (make-dummy-buffer))
  
         ;; Add the views to the box layout and to the window
         (gtk:gtk-box-pack-start active-buffer-container (gtk-object active-buffer) :expand t :fill t)
         (gtk:gtk-box-pack-start horizontal-box-layout panel-buffer-container-left :expand nil)
         (gtk:gtk-box-pack-start horizontal-box-layout active-buffer-container :expand t :fill t)
         (gtk:gtk-box-pack-start horizontal-box-layout panel-buffer-container-right :expand nil)
         (gtk:gtk-box-pack-start root-box-layout horizontal-box-layout :expand t :fill t)
  
  
negative.code:      (with-slots (gtk-object root-box-layout horizontal-box-layout
                    panel-buffer-container-left
                    panel-buffer-container-right
                    main-buffer-container
                    active-buffer prompt-buffer-container
                    prompt-buffer-view
                    status-buffer status-container
  