let (encrypted_signal, encrypted_recv) = tokio::sync::oneshot::channel();
    let join = tokio::spawn(session.run(stream, handler, Some(encrypted_signal)));
    encrypted_recv.await.unwrap_or(());

        join: tokio::spawn(session.run(stream, handler)),

        join,

        mut encrypted_signal: Option<tokio::sync::oneshot::Sender<()>>,

                    self = reply(self, &mut handler, &buf[..]).await?;

                    self = reply(self, &mut handler, &mut encrypted_signal, &buf[..]).await?;

    sender: &mut Option<tokio::sync::oneshot::Sender<()>>,

            if let Some(sender) = sender.take() {
                sender.send(()).unwrap_or(());
            }