anchor.diff:  
     // Prompt user to log in
     let linkAccount = Response.linkAccount (Some (Text "Please log in."))
  -  return Response.toRawResponse response None
  +  return response, None
   })
  
positive.code:       {
          Attributes = defaultArg attributes initialAttributes
          IsNewSession = request.session.``new``
          Original = request
        }
      parsedRequest, session
  
  
negative.code:   let linkAccount speechOption =
      { empty with Card = Some LinkAccount }
  
  type Handler<'a> = Request -> Session<'a> -> Async<Response * 'a>
  
  module Lambda =
    let ofHandler (defaultAttributes : 'a, handler : Handler<'a>) : Interop.LambdaHandler =
      Interop.createHandler (fun context request -> async {
        let request, session = Request.ofRawRequest defaultAttributes request
        let! response, attributes = handler request session
        return Response.toRawResponse response attributes
      })
  
  let handler = Lambda.ofHandler (None, fun request session -> async {
    let response =
      Response.say (Text "Hello world!")
      |> Response.withCard (
  