Attaching a patch. There's not much here. The two test lines do get invoked (I've set a breakpoint).
It's possible I'm subverting
AVRO-76 a bit. The plugin system seems to have been motivated in passing out of AVRO-band information between client and server. I'm using it to expose AVRO metadata to the client and server.
(One possible way of exposing client host/port information to the server would be to write a plugin that sticks that information into thread locals, say. We'd still need to share the information between RPCContext and Transceiver, but that doesn't seem too bad.)