armeria decorator with spring di

Question

In my armeria project (with spring for DI), i want to apply my decorator to specific services only.

@Component
class MyDecorator(
    @Autowired
    private val myRepository: Repository,
): DecoratingHttpServiceFunction {

    override fun serve(delegate: HttpService, ctx: ServiceRequestContext, req: HttpRequest): HttpResponse {
  //.. do something like authorization
    return delegate.serve(ctx, req)
  }
}

@ProducesJson
@Controller
// @PathPrefix("/a") no path prefix
class ARouter {
    @Get("/abc")
    fun sample(): String {
        return "A"
    }
}

@ProducesJson
@Controller
class BRouter {
    @Get("/bcd")
    fun sample(): String {
        return "B"
    }
}

@Configuration
class Config {

    @Bean
    fun armeriaConfig(
      //..
    ): ArmeriaServerConfigurator {
        return ArmeriaServerConfigurator { serverBuilder ->
           serverBuilder
           .decoratorUnder("/", myDecorator)
           // .decoratorUnder("/a", myDecorator) no path prefix

The above code applies myDecorator to all routers. Is there any way to allow MyDecorator to be applied only to ARouter? (There is no path prefix for each router.)