@router_b.get("/")
def get_b():
    return {"msg": "B"}


@router_c.get("/")
def get_c():
    return {"msg": "C"}


router_b.include_router(router=router_c, prefix="/c")
router_a.include_router(router=router_b, prefix="/b")
app.include_router(router=router_a, prefix="/a")


client = TestClient(app)


@pytest.mark.parametrize(
    "path,expected_status,expected_response",
    [

		route := &route.RouteConfiguration{}
		err = drc[i].RouteConfig.UnmarshalTo(route)
		if err != nil {
			return nil, err
		}
		sort.Slice(route.VirtualHosts, func(i, j int) bool {
			return route.VirtualHosts[i].Name < route.VirtualHosts[j].Name
		})
		drc[i].RouteConfig = protoconv.MessageToAny(route)
	}

	if stripVersions {
		for i := range drc {
			drc[i].VersionInfo = ""
			drc[i].LastUpdated = nil
		}
	}

			}
			routes = append(routes, routeTyped)
		}
	}
	if len(routes) == 0 {
		return nil, fmt.Errorf("no routes found")
	}
	sort.Slice(routes, func(i, j int) bool {
		iName, err := strconv.Atoi(routes[i].Name)
		if err != nil {
			return false
		}
		jName, err := strconv.Atoi(routes[j].Name)
		if err != nil {
			return false
		}
		return iName < jName
	})
	return routes, nil
}

		if err != nil {
			return err
		}
		istiodBytes.WriteString(istiod)
	}
	diff := difflib.UnifiedDiff{
		FromFile: "Istiod Routes",
		A:        difflib.SplitLines(istiodBytes.String()),
		ToFile:   "Envoy Routes",
		B:        difflib.SplitLines(envoyBytes.String()),
		Context:  c.context,
	}
	text, err := difflib.GetUnifiedDiffString(diff)
	if err != nil {
		return err
	}

        val route = Route(address, proxy, inetSocketAddress)
        if (routeDatabase.shouldPostpone(route)) {
          postponedRoutes += route
        } else {
          routes += route
        }
      }

      if (routes.isNotEmpty()) {
        break
      }
    }

    if (routes.isEmpty()) {
      // We've exhausted all Proxies so fallback to the postponed routes.
      routes += postponedRoutes

```Python hl_lines="35"
{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

!!! tip "Tipp"
    Beachten Sie, dass Sie nicht den Router selbst (`invoices_callback_router`) an `callback=` übergeben, sondern das Attribut `.routes`, wie in `invoices_callback_router.routes`.

### Es in der Dokumentation ansehen

import okhttp3.Response
import okhttp3.Route

class RecordingOkAuthenticator(
  val credential: String?,
  val scheme: String?,
) : Authenticator {
  val responses = mutableListOf<Response>()
  val routes = mutableListOf<Route>()

  fun onlyResponse() = responses.single()

  fun onlyRoute() = routes.single()

  @Throws(IOException::class)
  override fun authenticate(
    route: Route?,
    response: Response,

 "configs": [
  {
   "@type": "type.googleapis.com/envoy.admin.v3.RoutesConfigDump",
   "static_route_configs": [
    {
     "route_config": {
      "@type": "type.googleapis.com/envoy.config.route.v3.RouteConfiguration",
      "virtual_hosts": [
       {
        "name": "backend",
        "domains": [
         "*"
        ],
        "routes": [
         {
          "match": {
           "prefix": "/healthz/ready"
          },

 "configs": [
  {
   "@type": "type.googleapis.com/envoy.admin.v3.RoutesConfigDump",
   "static_route_configs": [
    {
     "route_config": {
      "@type": "type.googleapis.com/envoy.config.route.v3.RouteConfiguration",
      "virtual_hosts": [
       {
        "name": "backend",
        "domains": [
         "*"
        ],
        "routes": [
         {
          "match": {
           "prefix": "/healthz/ready"
          },

func getLinkWithDestinationOf(ip string) (netlink.Link, error) {
	routes, err := netlink.RouteListFiltered(
		netlink.FAMILY_V4,
		&netlink.Route{Dst: &net.IPNet{IP: net.ParseIP(ip), Mask: net.CIDRMask(32, 32)}},
		netlink.RT_FILTER_DST)
	if err != nil {
		return nil, err
	}

	if len(routes) == 0 {
		return nil, fmt.Errorf("no routes found for %s", ip)
	}

	linkIndex := routes[0].LinkIndex
	return netlink.LinkByIndex(linkIndex)
}