anchor.diff:  
   -endif. % SLF_COMMENT
   
  -%% @doc Fold over all the buckets.
  --spec fold_buckets(riak_kv_backend:fold_buckets_fun(),
  -                   any(),
  -                   [],
  -                   state()) -> {ok, any()} | {async, fun()} | {error, term()}.
  -fold_buckets(_FoldBucketsFun, Acc, _Opts, _S) ->
  -    Acc.                                        % lazy!
  -
   %% @doc Fold over all the keys for one or all buckets.
   -spec fold_keys(riak_kv_backend:fold_keys_fun(),
                   any(),
  
positive.code: -spec callback(reference(), any(), state()) -> {ok, state()}.
  callback(_Ref, _Term, S) ->
      {ok, S}.
  
  %% @spec location(state(), {riak_object:bucket(), riak_object:key()})
  %%          -> string()
  
negative.code:         {error, Err} -> {error, Err, State}
      end.
  
  
  
  %% @spec list(state()) -> [{Bucket :: riak_object:bucket(),
  %%                          Key :: riak_object:key()}]
  %% @doc Get a list of all bucket/key pairs stored by this backend
  list(#state{dir=Dir}) ->
      % this is slow slow slow
      %                                              B,N,N,N,K
      [location_to_bkey(X) || X <- filelib:wildcard("*/*/*/*/*",
                                                           Dir)].
  
  -ifdef(SLF_COMMENT).
  
  %% @spec list_bucket(state(), riak_object:bucket()) ->
  %%           [riak_object:key()]
  