How to get value out of Response?

Question

I would like to test my service, that have the following implementation:

  val health: HttpRoutes[IO] = HttpRoutes.of[IO] {
    case GET -> Root / "health" =>
      Ok(Stream
        .awakeEvery[IO](1.second)
        .flatMap { _ =>
          Stream
            .eval[IO, ServerHealth](checkServers(checkKafkaHealth)(checkSapHealth))
            .map(h => h.asJson)
        })
  }

and I would like test the service and I've tried as follows:

val req = Request[IO](method = Method.GET, uri = uri"/metric/health")
val res = MetricService(config)
            .health(req)

The question is, how to get the value from the response body?