tester.debugComponentTrees();
GeoServerDialog dialog = (GeoServerDialog) tester.getComponentFromLastRenderedPage("form:panel");
assertNotNull(dialog);
dialog.showOkCancel(new AjaxRequestTarget(tester.getLastRenderedPage()),
new DialogDelegate() {
@Override
protected Component getContents(String id) {
return new GeoServerFileChooser(id, new Model(root));
}