anchor.diff:      (unless (menu-previous-line 1)
         (return))
       (unmark-line (current-point))))
  -
  -(defun marked-menu-items (point indicator)
  -  (or (loop :for ov :in (buffer-value point 'mark-overlays)
  -            :collect (menu-property-at (overlay-start ov) indicator))
  -      (list (menu-property-at point indicator))))
  
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:            :menu-item
             :append-menu
             :append-menu-item
             :display-menu))
  (in-package :lem.menu-mode)
  
  (define-attribute head-line-attribute
  