anchor.diff:             :menu-item
              :append-menu
              :append-menu-item
  -           :display-menu
  -           :menu-property-at
  -           :marked-menu-items))
  +           :display-menu))
   (in-package :lem.menu-mode)
   
   (define-attribute head-line-attribute
  
positive.code:               (put-text-property start p 'plist (menu-item-plist item))))
            (move-to-line (buffer-point buffer) 2))))))
  
  (defun menu-property-at (point indicator)
    (with-point ((p point))
      (getf (text-property-at (line-start p) 'plist) indicator)))
  
  (defun menu-select-1 (set-buffer-fn)
    (alexandria:when-let ((fn (text-property-at (current-point) 'select-callback)))
      (funcall fn set-buffer-fn)))
  
negative.code:     (unless (menu-previous-line 1)
        (return))
      (unmark-line (current-point))))
  