anchor.diff:            keys = [],
             disable_login = false,
             disable_ui = false,
  -          return_url = undefined,
  -          use_referer = false,
  +          base_url = undefined,
   
             session = #watts_rsp_session{}
            }).
  
positive.code: 
  -record(watts_rsp_session, {
            referer = undefined,
            iss = undefined,
            sub = undefined,
            service_id = undefined,
  
negative.code: 
  
  new(#{id := Id, key_location := Location, disable_ui := DisableUi,
        disable_login := DisableLogin, base_url := BaseUrl}) ->
      case get_rsp_keys(Location) of
          {ok, Keys} ->
              {ok,  #watts_rsp{id = Id, key_location = Location,
                               keys = Keys, disable_login = DisableLogin,
                               disable_ui = DisableUi, base_url = BaseUrl
                              }};
          {error, Reason} ->
              {error, Reason}
  