anchor.diff:  %%      of them are ignored, as cyclon doesn't use / implements this features.
   -spec notify_change(_, _, State::state()) -> {ok, state()}.
   notify_change(_, _, State) ->
  +    %% Possible to use key range changes for rm_check() / rm_send_changes() ???
       {ok, State}.
   
   
  
positive.code: %%      of the form {selected_data, Instance, ExchangeData}.
  -spec select_data(State::state()) -> {ok, state()}.
  select_data(State) ->
      {ok, State}.
  
  
  
negative.code: -spec web_debug_info(state()) ->
      {KeyValueList::[{Key::string(), Value::any()},...], state()}.
  web_debug_info(State) ->
      %% web_debug_info (msg)
      {[{"Key", "Value"}], State}.
  
  
  