code: private List<ServletRegistrationProvider> getServletRegistrationProviders()
     {
        if (servletRegistrationProviders == null)
        {
           servletRegistrationProviders = Iterators.asList(
                    ServiceLoader.loadTypesafe(ServletRegistrationProvider.class).iterator());
           Collections.sort(servletRegistrationProviders, new WeightedComparator());
        }
        return servletRegistrationProviders;
     }
docs: Returns the list of {@link ServletRegistrationProvider} implementations.