anchor.diff:      lists:foldl(Output, ok, List),
       ok.
   
  +
  +%% @doc Add RSPs if enabled in the configuration.
  +%% Relaying Service Provider are only added if configured, else the
  +%% configured RSPs are not added to the running WaTTS instance.
  +%% @see add_rsps/0
  +-spec maybe_add_rsps(Enabled :: boolean() ) -> ok.
   maybe_add_rsps(true) ->
       add_rsps();
   maybe_add_rsps(_) ->
       ?SETCONFIG(rsp_list, []),
       ok.
   
  -
  +%% @doc Add the configured RSPs as they are enabled in the config.
  +%% The function iterates through the configuration and updates them.
  +%% No keys are fetched yet, only the configuration is updated.
  +%% @see watts_rsp:new/1
  +%% @see watts_rsp
  +-spec add_rsps() -> ok.
   add_rsps() ->
       lager:info("Init: adding relying service provider (RSP)"),
       UpdateRsp =
  
positive.code:                 lager:info("Init: ~p will not be used for login", [Id]);
              false ->
                  ok
          end,
          add_openid_provider(T, LocalEndpoint)
      catch Error:Reason ->
              Msg = "Init: error occured OpenId Connect provider ~p: '~p' ~p",
              lager:critical(Msg, [Id, Error, Reason])
      end;
  add_openid_provider([], _) ->
      ok.
  
  
  wait_and_log_provider_results() ->
      {ok, List} = oidcc:get_openid_provider_list(),
      Max = erlang:system_time(seconds) + ?CONFIG(max_provider_wait, 5),
      ok = wait_and_log_provider_results(List, [], Max),
      ok.
  
  wait_and_log_provider_results([], [], _Max) ->
      ok;
  wait_and_log_provider_results([], List, Max) ->
  
negative.code:     end,
      ok.
  
  %% @doc add the configured openid provider.
  %% this function iterates throught the configured providers and
  %% adds each of them. Then waits for the results so the provider can
  %% read the needed configs from the Internet in parallel.
  %% @see add_openid_provider/2
  %% @see wait_and_log_provider_results/0
  -spec add_openid_provider() -> ok.
  add_openid_provider() ->
      lager:info("Init: adding openid provider"),
      %% force only one try
  