anchor.diff:                               load_nodes()
                        end,
   
  -    [?_assertEqual([], load_nodes(<<"/tmp/probably/does/not/exist.json">>)),
  +    [?_assertEqual(maps:new(), load_nodes(<<"/tmp/probably/does/not/exist.json">>)),
        ?_assertEqual(Nodes, PersistAndLoad(Nodes))
       ].
   
  
positive.code:     end.
  
  
  -spec load_nodes() -> [node_info()].
  load_nodes() ->
      load_nodes(?PERSIST_FILE).
  
  
  -spec load_nodes(binary()) -> [node_info()].
  load_nodes(File) ->
      case file:open(File, [read, binary, raw]) of
          {ok, IO} ->
  
negative.code:             end;
          {error, enoent} ->
              % file does not exist -> this is totally alright
              maps:new();
          Error ->
              lager:warning("error on loading nodes file: ~p", [Error]),
              maps:new()
      end.
  
  
  