anchor.diff:  code_change(_OldVsn, State, _Extra) ->
       {ok, State}.
   
  +%% @doc start the configuration of WaTTS if it has not been started before.
  +%% If it has been started before, the configuration crashed, which means
  +%% that something unexpected happened. As this is a critical issue WaTTS
  +%% will be stoppped then.
  +-spec start_if_not_started_before() -> ok.
  +start_if_not_started_before() ->
  +    start_if_undefined(?CONFIG(watts_init_started)).
  +
  +%% @doc only start if the special configuration `watts_init_started' is not set.
  +-spec start_if_undefined(Started :: undefined | any()) -> ok.
  +start_if_undefined(undefined) ->
  +    ok = ?SETCONFIG(watts_init_started, true),
  +    gen_server:cast(self(), start_watts);
  +start_if_undefined(_) ->
  +    lager:emergency("Init: restarting ... this should not happen!"),
  +    erlang:halt(255).
  +
  +%% @doc start initalization of WaTTS.
  +%% This copies the version from keys to environment and enforces security
  +%% @see enforce_security/0
  +-spec init_watts() -> ok.
   init_watts() ->
       lager:info("Init: starting  "),
       %% copy the version into the config
  
positive.code:                      true
               end,
      lists:filter(Filter, List).
  
  start_if_not_started_before() ->
      start_if_undefined(?CONFIG(watts_init_started)).
  
  start_if_undefined(undefined) ->
      ok = ?SETCONFIG(watts_init_started, true),
      gen_server:cast(self(), start_watts);
  start_if_undefined(_) ->
      lager:emergency("Init: restarting ... this should not happen!"),
      erlang:halt(1).
  
negative.code:     lager:debug("Init: config = ~p", [?ALLCONFIG]),
      ok.
  
  %% @doc enforces WaTTS to run in a secure setting.
  %% This includes running as non root user and having SSL configured.
  %% If SSL is not configured it will be forced to localhost.
  %% @see maybe_change_hostname/3
  %% @see error_if_running_as_root/0
  -spec enforce_security() -> ok.
  enforce_security() ->
      SSL = ?CONFIG(ssl),
      Hostname0 = ?CONFIG(hostname),
  