anchor.diff:      %%     Plain ->
       %%         HashKey = Key = Plain
       %% end,
  -    DocIdx = riak_core_util:chash_std_keyfun({Bucket, Key}),
  -    Preflist = lists:sublist(riak_core_ring:preflist(DocIdx, Ring), N),
  -    PrefIdxes = [I || {I, _} <- Preflist],
  +    PrefIdxes = calc_bkey_to_prefidxes(Bucket, Key, Ring, N),
       case lists:member(Idx, PrefIdxes) of
           true  ->
               Key;
  
positive.code:                   backend_flags = BackendFlags,
                    data_dir = DataDir,
                    idxes_to_do = [Idx|Idxes]} = S0) ->
      ?DEBUG("rotate_idx: Id ~p self() ~p old_idx ~p\n", [S0#state.id, self(), S0#state.idx]),
      S1 = stop_idx(S0),
      basho_bench_keygen:reset_sequential_int_state(),
      Handle = start_idx(Backend, BackendFlags, DataDir, Idx),
  
negative.code:                                                     NewMD),
                                      <<42:32/big>>))}.
  
  calc_bkey_to_prefidxes(Bucket, Key, RingSize, N) when is_integer(RingSize) ->
      calc_bkey_to_prefidxes(Bucket, Key, riak_core_ring:fresh(RingSize, nonode),
                             N);
  calc_bkey_to_prefidxes(Bucket, Key, Ring, N) ->
      DocIdx = riak_core_util:chash_std_keyfun({Bucket, Key}),
      Preflist = lists:sublist(riak_core_ring:preflist(DocIdx, Ring), N),
      [I || {I, _} <- Preflist].
  