anchor.diff:  
   insert_metric(Registry, Name, LabelValues, Value, ConflictCB) ->
     prometheus_metric:check_mf_exists(?TABLE, Registry, Name, LabelValues),
  -  case ets:insert_new(?TABLE, {{Registry, Name, LabelValues}, Value}) of
  +  case ets:insert_new(?TABLE, {key(Registry, Name, LabelValues), Value}) of
       false -> %% some sneaky process already inserted
         ConflictCB(Registry, Name, LabelValues, Value);
       true ->
         ok
     end.
   
  +key(Registry, Name, LabelValues) ->
  +  X = erlang:system_info(scheduler_id),
  +  Rnd = X band (?WIDTH-1),
  +  {Registry, Name, LabelValues, Rnd}.
  +
  +collect_unique_labels(MFValues) ->
  +  lists:usort([L || [L, _] <- MFValues]).
  +
  +reduce_label_values(Labels, MFValues) ->
  +  lists:sum([Y || [L, Y] <- MFValues, L == Labels]).
  +
   create_counter(Name, Help, Data) ->
     create_mf(Name, Help, counter, ?MODULE, Data).
  
positive.code: %%====================================================================
  
  dinc_impl(Registry, Name, LabelValues, Value) ->
    case ets:lookup(?TABLE, {Registry, Name, LabelValues}) of
      [{_Key, OldValue}] ->
        ets:update_element(?TABLE, {Registry, Name, LabelValues},
                           {?SUM_POS, Value + OldValue});
      [] ->
        insert_metric(Registry, Name, LabelValues, Value, fun dinc_impl/4)
  
negative.code: %% @end
  reset(Registry, Name, LabelValues) ->
    prometheus_metric:check_mf_exists(?TABLE, Registry, Name, LabelValues),
    Schedulers = erlang:system_info(schedulers),
    case lists:usort([ets:update_element(?TABLE,
                                         {Registry, Name, LabelValues, Scheduler},
                                         {?SUM_POS, 0})
                      || Scheduler <- lists:seq(1, Schedulers)]) of
      [_, _] -> true;
      [true] -> true;
      _ -> false
    end.
  
  %% @equiv value(default, Name, [])
  value(Name) ->
  