Tiny comment nits.

src/proto/server/client.rs

@@ -134,10 +134,9 @@ impl Client {
     S: Stream<Item = ServerRequest> + Unpin,
   {
     Box::pin(async_stream::try_stream! {
+      // Drive the main loop: send requests and receive responses.
       loop {
         match self.run_once(&mut request_stream).await? {
-          // TODO: Close frame stream connection when we break, so that the
-          // other side notices we've gone away.
           RunOnceResult::Break => break,
           RunOnceResult::Continue => continue,
           RunOnceResult::Response(response) => yield response,