anchor.diff:      (mapc #'clear-screen (window-list))
       (mapc #'clear-screen (frame-floating-windows (current-frame)))))
   
  -(defgeneric %delete-window (window))
  -(defgeneric window-redraw (window force)
  -  (:method (window force)
  -    (redraw-display-window window force)))
  -
   (defun window-view (window)
     (screen-view (window-screen window)))
   
  
positive.code:         (redraw-all-windows)
          (notify-frame-redraw-finished (current-frame))))))
  
  (defun display-popup-message (buffer-or-string
                                &key (timeout *default-popup-message-timeout*)
                                     (gravity :cursor)
  
negative.code:           (setf (window-tree) (funcall another-getter))
            (funcall setter2 (funcall another-getter))))))
  
  (defun collect-left-windows (window-list)
    (lem-utils:min-if #'window-x window-list))
  
  