[HTTPS-Everywhere] How do testurls for partial TLS support look like?

[Numismatika]

Hey,
now that ruleset updates need to have testurls, i have a small problem.

Some pages redirect to http when accessing them at the toplayer,
https://www.example.org/ redirects to http://www.example.org
but https://www.example.org/images/23as.jpg would be fine.
Do we have to find a static file that is likely to stay for the
test-case, or how would a testurl in this case look like?
Regards,
Numismatika