emacs-library-link WidgetSyntax:
type ::= (emacs-library-link [keyword argument]... file)
A widget to represent a link to an Emacs Lisp file. Its super is the
link widget.
It overrides the :action property, to a function to find the file
file.
Example:
(widget-create 'emacs-library-link
:button-prefix ""
:button-suffix ""
:tag "Show yourself, Widget Library!"
"wid-edit.el")