anchor.diff:  %% @doc Generate the folding function
   %% for a riak fold_req
   -spec fold_fun(pid(), boolean()) -> fun().
  -fold_fun(Tree, _HasIndexTree = false) ->
  -    ObjectFoldFun = object_fold_fun(Tree),
  +fold_fun(HashtreePid, _HasIndexTree = false) ->
  +    ObjectFoldFun = object_fold_fun(HashtreePid),
       {Limit, Wait} = get_build_throttle(),
       fun(BKey, RObj, Acc) ->
               BinBKey = term_to_binary(BKey),
  
positive.code:             Acc2 = maybe_throttle_build(RObj, Limit, Wait, Acc),
              Acc2
      end;
  fold_fun(Tree, _HasIndexTree = true) ->
      %% Index AAE backend, so hash the indexes
      ObjectFoldFun = object_fold_fun(Tree),
      IndexFoldFun = index_fold_fun(Tree),
      {Limit, Wait} = get_build_throttle(),
      fun(BKey = {Bucket, Key}, BinObj, Acc) ->
              RObj = riak_object:from_binary(Bucket, Key, BinObj),
  
negative.code: 
  -spec maybe_build(state()) -> state().
  maybe_build(State=#state{built=false}) ->
      HashtreePid = self(),
      Pid = spawn_link(fun() ->
                               build_or_rehash(HashtreePid, State)
                       end),
      State#state{built=Pid};
  maybe_build(State) ->
  