Ok That's what I did observe too. Thx.

It seems strange that there is nothing in the documentation explaining the fact that `[NSURLSession sharedSession]` uses the `NSURLProtocol` classes registered using `[NSURLProtocol registerClass:]` and not the classes set in its `.configuration.protocolClasses` as other `NSURLSession` does.

I think I'll send a feedback to Apple about that missing info in the doc (and you may do the same)