How to annotate injector.getInstance?

I want to inject an instance from Guice injector in my unitTest.

Which diffrentiator can I use?

I know @annotation mechanism is used in ctor params

but junit doesn't allow ctor with params.

should I use class fields' @annotation?

 public void setUp() throws Exception {
    RoutingResponseRepository routingResponseRepository = injector.getInstance(RoutingResponseRepository.class);
}

e.g.

I want

@firstType RoutingResponseRepository

and

@secondType RoutingResponseRepository