code: public ContainerWrapper findContainer(AppContextWrapper sc) {
  		ContainerRegistryBuilder cb = (ContainerRegistryBuilder) sc.getAttribute(ContainerRegistryBuilder.APPLICATION_CONTEXT_ATTRIBUTE_NAME);
  		if (cb == null)
  			cb = prepare(sc);
  		launch(sc, cb);
  		return cb.getContainerWrapper();
  	}
docs: lazy startup container when first time the method is called, it will
  startup the container
  
  @param sc
  ServletContext
  @return ContainerWrapper
  @throws Exception