anchor.diff:  -record(state, {
             sub = undefined,
             iss = undefined,
  +          id = undefined,
             user_info = #{},
             credentials = [],
             sessions = []
  
positive.code: 
  %% API.
  
  -spec start_link(User :: term()) -> {ok, pid()}.
  start_link({Subject, Issuer}) ->
  	gen_server:start_link(?MODULE, [Subject, Issuer], []).
  
  -spec set_user_info(UserInfo :: map(), Pid :: pid()) -> ok.
  set_user_info(Info, Pid) ->
  
negative.code: handle_info(_Info, State) ->
  	{noreply, State}.
  
  terminate(_Reason, #state{id = Id}) ->
      tts_user_mgr:user_shutting_down(Id),
  	ok.
  
  code_change(_OldVsn, State, _Extra) ->
  