a group as node of a tree widget

[Masatake YAMATO]

Is it possible to use a group widget as node of tree widget?

As far as trying following code, a group widget is not handled well.

(defun tree-test ()
  (interactive)

  (switch-to-buffer "TREE-GROUP-NODE-TEST")
  
  (kill-all-local-variables)
  (let ((inhibit-read-only t))
    (erase-buffer))

  (widget-create
   'tree-widget 
   :open t
   :node '(group (push-button
                  :tag "Root"
                  :format "%[%t%]\n")))

  (use-local-map widget-keymap)
  (widget-setup))

M-x tree-test and click "Root" node. Then string "Root" is gone.

Masatake YAMATO