pub fn new<S>(svc: S) -> Self
    where
        S: Service<Request<Body>, Error = Infallible>
            + NamedService
            + Clone
            + Send
            + Sync
            + 'static,
        S::Response: axum::response::IntoResponse,
        S::Future: Send + 'static,
    {
        Self::default().add_service(svc)
    }
Create a new routes with `svc` already added to it.
tonic/src/service/router.rs