@Test
    void components_are_shared() {
        ComponentGraph componentGraph = new ComponentGraph();
        componentGraph.add(mockComponentNode(SimpleComponent.class));
        componentGraph.complete();

        SimpleComponent instance1 = componentGraph.getInstance(SimpleComponent.class);
        SimpleComponent instance2 = componentGraph.getInstance(SimpleComponent.class);
        assertSame(instance1, instance2);
    }
@author gjoranv
@author Tony Vaagenes
@author ollivir
container-core/src/test/java/com/yahoo/container/di/componentgraph/core/ComponentGraphTest.java