how to forward declare a route, i.e., a route with no endpoint.

[sandeep-gh]

Due to circular dependency I need to declare a "dummy/placeholder" endpoint which is later defined. Kind of like forward declaration of types. Below is the sample code:

from starlette.applications import Starlette
from starlette.responses import JSONResponse
from starlette.routing import Route
from starlette.testclient import TestClient

app = Starlette()

app.router.routes.append(Route("/", None, name="deferred_route"))

async def deferred_endpoint(request):
    return JSONResponse({"message": "Deferred Endpoint"})

Y = app.router.routes[0]
Y.endpoint = deferred_endpoint
client = TestClient(app)

This doesn't work. What would be a good way to achieve this. Something like route.update_endpoint()?