code: private void issueSessionError(
              ChannelHandlerContext ctx, SpdySessionStatus status) {
  
          sendGoAwayFrame(ctx, status).addListener(new ClosingChannelFutureListener(ctx, ctx.newPromise()));
      }
docs: /*
  SPDY Session Error Handling:
  
  When a session error occurs, the endpoint encountering the error must first
  send a GOAWAY frame with the Stream-ID of the most recently received stream
  from the remote endpoint, and the error code for why the session is terminating.
  
  After sending the GOAWAY frame, the endpoint must close the TCP connection.