public OpenConfigComponentsHandler addComponent(OpenConfigComponentHandler component) {
        modelObject.addToComponent(component.getModelObject());
        return this;
    }
@Test
    public void testAddComponent() {
        // test Handler
        OpenConfigComponentsHandler components = new OpenConfigComponentsHandler();

        // call addComponent
        OpenConfigComponentHandler component = new OpenConfigComponentHandler("name", components);

        // expected ModelObject
        DefaultComponents modelObject = new DefaultComponents();
        DefaultComponent comp = new DefaultComponent();
        comp.name("name");
        modelObject.addToComponent(comp);

        assertEquals("[NG]addComponent:ModelObject(Component added) is not an expected one.\n",
                     modelObject, components.getModelObject());
    }