@Test
    void previous_graph_is_retained_when_new_graph_throws_exception_for_missing_config() {
        ComponentEntry simpleComponentEntry = new ComponentEntry("simpleComponent", SimpleComponent.class);

        writeBootstrapConfigs(simpleComponentEntry);
        Container container = newContainer(dirConfigSource);
        ComponentGraph currentGraph = getNewComponentGraph(container);

        currentGraph.getInstance(SimpleComponent.class);

        writeBootstrapConfigs("thrower", ComponentThrowingExceptionForMissingConfig.class);
        dirConfigSource.writeConfig("test", "stringVal \"myString\"");
        container.reloadConfig(2);
        assertNewComponentGraphFails(container, currentGraph, ConfigFutureException.class);
        assertEquals(1, currentGraph.generation());

        container.shutdownConfigRetriever();
        container.shutdown(currentGraph);
    }
@author Tony Vaagenes
@author gjoranv
@author ollivir
container-core/src/test/java/com/yahoo/container/di/ContainerTest.java