code: public static void setServiceProviderFinder(ExternalContext ectx, ServiceProviderFinder slp)
      {
          ectx.getApplicationMap().put(SERVICE_PROVIDER_KEY, slp);
      }
docs: Set a ServiceProviderFinder to the current application, to locate
  SPI service providers used by MyFaces.
  
  This method should be called before the web application is initialized,
  specifically before AbstractFacesInitializer.initFaces(ServletContext)
  otherwise it will have no effect.
  
  @param ectx
  @param slp