anchor.diff:  (defmethod initialize-instance :after ((obj poem-selector) &key &allow-other-keys)
     (setf (widget-children obj :poems)
           (mapcar (lambda (poem)
  -                  (make-foldable-poem-widget obj
  -                                             poem
  +                  (make-foldable-poem-widget poem
                                                (poem-selector-poem-widget-class obj)
                                                :folded))
                   (find-persistent-objects *store* 'poem)))
  
positive.code: (defmethod render-widget-body ((obj poem-selector) &rest args)
    (declare (ignore args))
    (with-html
      (:div :class "poem-selector"
        (:h2 "Selected Poems")
        (:p "Here you may find a very personal collection of poems I like."))))
  
  (defmethod render-widget-children ((obj poem-selector) &rest args)
    (with-html (:hr))
  
negative.code:   (ecase (mode widget)
      (:show
       (with-html
         (:div :class "dismiss-button"
           (render-link (f_% (setf (mode widget) :folded))
                        "Dismiss"))
         (render-widget (poem-widget widget))))
      (:folded
       (let ((poem (poem (poem-widget widget))))
         (with-html
           (render-link (f_% (setf (mode widget) :show))
                        (or (poem-title poem)
                            (concatenate
                             'string
                             "["
                             (subseq (poem-body poem)
                                     0
                                     (or (position #\Newline (poem-body poem))
                                         (length (poem-body poem))))
                             "]")))
           " by "
           (str (poem-author poem)))))))
  
  (defun make-foldable-poem-widget (poem poem-widget-class mode)
    (let ((widget (make-instance 'foldable-poem-widget
                                 :poem-widget (make-instance poem-widget-class
                                                             :poem poem)
  