code: @Test public void testInterfaceClass() throws Exception {
    ServiceConfig<Greeting> service=new ServiceConfig<Greeting>();
    service.setInterface(Greeting.class.getName());
    service.setRef(Mockito.mock(Greeting.class));
    assertThat(service.getInterfaceClass() == Greeting.class,is(true));
    service=new ServiceConfig<Greeting>();
    service.setRef(Mockito.mock(Greeting.class,withSettings().extraInterfaces(GenericService.class)));
    assertThat(service.getInterfaceClass() == GenericService.class,is(true));
  }
  