List<IAjaxCallListener> ajaxCallListeners = attributes.getAjaxCallListeners();
for (IAjaxCallListener ajaxCallListener : ajaxCallListeners)
{
if (ajaxCallListener instanceof IComponentAwareHeaderContributor)
{
IComponentAwareHeaderContributor contributor = (IComponentAwareHeaderContributor)ajaxCallListener;
contributor.renderHead(component, response);
}
}
}