config-servlet/src/main/java/org/ocpsoft/rewrite/servlet/config/ServletMapping.java
private List<ServletRegistration> getServletRegistration(ServletContext context)
   {
      for (ServletRegistrationProvider provider : getServletRegistrationProviders())
      {
         List<ServletRegistration> registrations = provider.getServletRegistrations(context);
         if (registrations != null)
         {
            return registrations;
         }
      }
      throw new IllegalStateException("Unable to find the Servlet registrations of the application");
   }
private List<ServletRegistration> getServletRegistration(ServletContext context)
   {
      for (ServletRegistrationProvider provider : getServletRegistrationProviders())
      {
         List<ServletRegistration> registrations = provider.getServletRegistrations(context);
         if (registrations != null)
         {
            return registrations;
         }
      }
      throw new IllegalStateException("Unable to find the Servlet registrations of the application");
   }
Obtains the list of registered {@link Servlet} instances using the {@link ServletRegistrationProvider} SPI.