anchor.diff:      SamplesNum = 10,
       Samples = get_stats_raw(PoolId, BucketId, SamplesNum),
       OpsPerSec = avg(deltas(sum_stats_ops(Samples))),
  -    EvictionsPerSec = avg(deltas(proplists:get_value("evictions", Samples))),
  -    CurBytes = erlang:max(avg(proplists:get_value("bytes", Samples)),
  -                          1),
  -    MaxBytes = erlang:max(avg(proplists:get_value("limit_maxbytes", Samples)),
  +    EvictionsPerSec = avg(deltas(default_find("evictions", Samples))),
  +    CurBytes = erlang:max(avg(default_find("bytes", Samples)), 1),
  +    MaxBytes = erlang:max(avg(default_find("limit_maxbytes", Samples)),
                             CurBytes),
       [{cacheSize, NumNodes * MbPerNode},
        {opsPerSec, OpsPerSec},
  
positive.code:                "cmd_flush"],
                Stats).
  
  sum_stats([Key | Rest], Stats) ->
      sum_stats(Rest, Stats, proplists:get_value(Key, Stats)).
  
  sum_stats([Key | Rest], Stats, undefined) ->
      sum_stats(Rest, Stats, proplists:get_value(Key, Stats));
  sum_stats([], _Stats, undefined)    -> [];
  sum_stats([], _Stats, Acc)          -> Acc;
  sum_stats([Key | Rest], Stats, Acc) ->
      case proplists:get_value(Key, Stats) of
          undefined ->
              sum_stats(Rest, Stats, Acc);
          KeyStats ->
              Acc2 = lists:zipwith(fun(undefined, undefined) -> Acc;
                                      (undefined, _)         -> Acc;
                                      (_,         undefined) -> Acc;
                                      (X, Y) -> X + Y end, KeyStats, Acc),
              sum_stats(Rest, Stats, Acc2)
      end.
  
  avg(undefined) -> 0.0;
  avg(L)         -> avg(L, 0, 0).
  
negative.code: %  ...]
  
  get_stats_raw(_PoolId, BucketId, SamplesNum) ->
      stats_aggregator:get_stats(BucketId, SamplesNum).
  
  sum_stats_ops(Stats) ->
      sum_stats(["cmd_get", "cmd_set",
  