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: %% @private
  deregister_cleanup(Registry) ->
    prometheus_metric:deregister_mf(?TABLE, Registry),
    true = ets:match_delete(?TABLE, {{Registry, '_', '_'}, '_'}),
    ok.
  
  %% @private
  
negative.code: 
  -define(TABLE, ?PROMETHEUS_COUNTER_TABLE).
  -define(SUM_POS, 2).
  -define(WIDTH, 16).
  
  %%====================================================================
  %% Metric API
  