code: public List<ServiceRefType<WebAppDescriptor>> getAllServiceRef()
     {
        List<ServiceRefType<WebAppDescriptor>> list = new ArrayList<ServiceRefType<WebAppDescriptor>>();
        List<Node> nodeList = model.get("service-ref");
        for(Node node: nodeList)
        {
           ServiceRefType<WebAppDescriptor>  type = new ServiceRefTypeImpl<WebAppDescriptor>(this, "service-ref", model, node);
           list.add(type);
        }
        return list;
     }
docs: Returns all <code>service-ref</code> elements
  @return list of <code>service-ref</code>