anchor.diff:                   registry_collect_callback(Fd, Registry, Collector)
                end,
     prometheus_registry:collect(Registry, Callback),
  -  file:write(Fd, io_lib:format("\n", [])),
  +  file:write(Fd, "\n"),
     {ok, Size} = ram_file:get_size(Fd),
     {ok, Str} = file:pread(Fd, 0, Size),
     ok = file:close(Fd),
  
positive.code: 
  %% @private
  emit_mf_prologue(Fd, #'MetricFamily'{name=Name, help=Help, type=Type}) ->
    Bytes = io_lib:format("# TYPE ~s ~s\n# HELP ~s ~s\n",
                          [Name, string_type(Type),
                           Name, escape_metric_help(Help)]),
    file:write(Fd, Bytes).
  
  %% @private
  
negative.code:   ?ESCAPE_LVALUE(LValue);
  escape_label_value(LValue) when is_binary(LValue) ->
    ?ESCAPE_LVALUE(LValue);
  escape_label_value(Value) ->
    erlang:error({wtf, Value}).
  
  
  -spec sub(iodata(), string(), string()) -> string().
  sub(Str, Old, New) ->
  