anchor.diff:                       0 0))))
   
   (defun lem-pane-char-size (lem-pane)
  -  (maybe-update-cache-font lem-pane)
  +  (update-font-if-required lem-pane)
     (destructuring-bind (left top right bottom)
         (lem-pane-string-extent lem-pane)
       (values (- right left)
  
positive.code: (defun key-press (self x y gesture-spec)
    (declare (ignore self x y))
    (with-error-handler ()
      (alexandria:when-let ((key (gesture-spec-to-key gesture-spec)))
        (lem:send-event key))))
  
  (defun lem-pane-width (lem-pane)
  
negative.code:    nil
     (lambda ()
       (if attribute
           (let ((foreground (convert-color (lem:attribute-foreground attribute)
                                            (capi:simple-pane-foreground lem-pane)))
                 (background (convert-color (lem:attribute-background attribute)
                                            (capi:simple-pane-background lem-pane)))
                 (underline-p (lem:attribute-underline-p attribute))
                 (bold-p (lem:attribute-bold-p attribute))
                 (reverse-p (lem:attribute-reverse-p attribute)))
  