Oh, I see. create_connection(..., ssl=True) creates a default SSLContext,
but create_server(..., ssl=True) is invalid, it requires
ssl=SSLContext(...). I like the latter for connect_accepted_socket(). I
think Jim will happily comply.

What would happen if some other socket type was passed? Would anything go
wrong, assuming it's a socket type that understands connections? (I think
checking for SOCK_STREAM is more important maybe).