`aiohttp-cors` accesses the aiohttp protected `self._routes`

[bdraco]

aiohttp-cors/aiohttp_cors/urldispatcher_router_adapter.py

Line 187 in 38c6c17

preflight_route = resource._routes[hdrs.METH_OPTIONS]

          > `aiohttp-cors` accesses the protected `self._routes` here and relies on being able to add new methods

We could just update that library?

Originally posted by @Dreamsorcerer in aio-libs/aiohttp#9972 (comment)

[bdraco]

We may need to expose a public method in aiohttp for this so this library doesn't need to access the protected one

[asvetlov]

Good finding!
IIRC a resource can iterate over routes; it works but could be inefficient for the library.
Adding resource.routes property that returns a read-only mapping looks like a reasonable addition to me.