anchor.diff:                              Pair -> Pair;
                               Sentinel -> Sentinel;
                               {K, Data} ->
  -                                {K, merge_vclocks(Data, OldValue)}
  +                                {K, increment_vclock(Data, OldValue)}
                           end
                   end,
       update(fun (Config) -> misc:mapfilter(UpdateFun, Sentinel, Config) end).
  
positive.code: strip_metadata(Value) ->
      Value.
  
  %% Set the vclock in NewValue to one that descends from both and that
  %% neither descends from
  merge_vclocks(NewValue, OldValue) ->
      case is_list(NewValue) of
          true ->
  
negative.code: 
  set(KVList) ->
      ok = update(fun (Config) ->
                     misc:ukeymergewith(fun ({K, V}, {_, V}) ->
                                                {K, V};
                                            ({K, V1}, {_, V2}) ->
                                                {K, increment_vclock(V1, V2)}
                                        end, 1,
                                        lists:ukeysort(1, KVList),
                                        lists:ukeysort(1, Config))
  