WrapHandler中的Go-micro Opentracing用法

Question

From the documentation on opentracing, it's unclear on how I might be able to implement opentracing via a WrapHandler within a service definition. I already have an authentication WrapHandler, however this is custom, and not a plugin provided by micro. I have tried the below, but this does not work:

tracer := opentracing.GlobalTracer()

srv := micro.NewService(

    micro.Name("example.service"),
    micro.Version("latest"),
    micro.WrapHandler(tracing.NewHandlerWrapper(tracer)),
    micro.WrapHandler(AuthWrapper),
)

srv.Init()

Help much appreciated!