anchor.diff:      SleepMS = crypto:rand_uniform(MeanSleepMS - Delta, MeanSleepMS + Delta),
       lager:debug("maybe_backpressure_sleep: Siblings=~p, SleepMS=~p~n", [Siblings, SleepMS]),
       ok = riak_cs_stats:update(manifest_siblings_bp_sleep, SleepMS * 1000),
  -    timer:sleep(SleepMS).
  +    ok = timer:sleep(SleepMS),
  +    true.
   
   update(RcPid, OldManifests, OldRiakObject, WrappedManifests, Bucket, Key) ->
       NewManiAdded = riak_cs_manifest_resolution:resolve([WrappedManifests, OldManifests]),
  
positive.code:             {PutResult, undefined, undefined}
      end.
  
  maybe_backpressure_sleep(Siblings) ->
      BackpressureThreshold = riak_cs_config:get_env(
                                riak_cs, manifest_siblings_bp_threashold, 5),
      maybe_backpressure_sleep(Siblings, BackpressureThreshold).
  
  maybe_backpressure_sleep(Siblings, BackpressureThreshold)
    when Siblings < BackpressureThreshold ->
      ok;
  maybe_backpressure_sleep(Siblings, _BackpressureThreshold) ->
      MaxSleep = riak_cs_config:get_env(riak_cs, manifest_siblings_bp_max_sleep, 30*1000),
      Coefficient = riak_cs_config:get_env(riak_cs, manifest_siblings_bp_coefficient, 200),
  
negative.code:         {ok, RiakObject, Manifests} ->
              case update(RcPid, Manifests, RiakObject, WrappedManifests, Bucket, Key) of
                  {ok, _, _} = Res ->
                      case maybe_backpressure_sleep(riakc_obj:value_count(RiakObject)) of
                          true ->
                              %% Backpressure sleep has been triggered. Current object
                              %% is to be discarded to prevent unnecessary interleaving
                              %% with other concurrent manifest updates while sleeping.
                              {ok, undefined, undefined};
                          false ->
                              Res
                      end;
                  OtherRes ->
                      OtherRes
              end;
  