<wicket:extend xmlns:wicket="http://wicket.apache.org">
This page has three panels. Depending on the roles of the selected user, you either see one, two or three of them.
<span wicket:id="forAllUsersPanel">
panel for all users here
</span>
<span wicket:id="forAdminsAndUsersPanel">
panel for roles ADMIN and USER here
</span>
<span wicket:id="forAdminsPanel">
panel for only role ADMIN here
</span>
</wicket:extend>