code: public PortletCollectionType<SecurityConstraintType<T>> getOrCreatePortletCollection()
     {
        Node node = childNode.getOrCreate("portlet-collection");
        PortletCollectionType<SecurityConstraintType<T>> portletCollection = new PortletCollectionTypeImpl<SecurityConstraintType<T>>(this, "portlet-collection", childNode, node);
        return portletCollection;
     }
docs: If not already created, a new <code>portlet-collection</code> element with the given value will be created.
  Otherwise, the existing <code>portlet-collection</code> element will be returned.
  @return  a new or existing instance of <code>PortletCollectionType<SecurityConstraintType<T>></code>