anchor.diff:      fun(_, Key, Buffer) ->
               BufferMod:add(Key, Buffer)
       end;
  -fold_fun({keys, RecoverTsFun}, BufferMod, none, undefined) ->
  -    fun(_, Key, Buffer) ->
  -            CompoundKey = RecoverTsFun(Key),
  -            BufferMod:add(CompoundKey, Buffer)
  -    end;
   fold_fun(keys, BufferMod, none, {Bucket, Index, N, NumPartitions}) ->
       fun(_, Key, Buffer) ->
               Hash = riak_core_util:chash_key({Bucket, Key}),
               case riak_core_ring:future_index(Hash, Index, N, NumPartitions, NumPartitions) of
                   Index ->
                       BufferMod:add(Key, Buffer);
  -                _ ->
  -                    Buffer
  -            end
  -    end;
  -fold_fun({keys, RecoverTsFun}, BufferMod, none, {Bucket, Index, N, NumPartitions}) ->
  -    fun(_, Key, Buffer) ->
  -            Hash = riak_core_util:chash_key({Bucket, Key}),
  -            case riak_core_ring:future_index(Hash, Index, N, NumPartitions, NumPartitions) of
  -                Index ->
  -                    CompoundKey = RecoverTsFun(Key),
  -                    BufferMod:add(CompoundKey, Buffer);
                   _ ->
                       Buffer
               end
  
positive.code:                     case Filter(Key) of
                          true ->
                              BufferMod:add(Key, Buffer);
                          false ->
                              Buffer
                      end;
                  _ ->
                      Buffer
              end
      end;
  fold_fun({keys, RecoverTsFun}, BufferMod, Filter, {Bucket, Index, N, NumPartitions}) ->
      fun(_, Key, Buffer) ->
              Hash = riak_core_util:chash_key({Bucket, Key}),
              case riak_core_ring:future_index(Hash, Index, N, NumPartitions, NumPartitions) of
                  Index ->
                      CompoundKey = RecoverTsFun(Key),
                      case Filter(CompoundKey) of
                          true ->
                              BufferMod:add(CompoundKey, Buffer);
                          false ->
                              Buffer
                      end;
  
negative.code:                     Buffer
              end
      end;
  fold_fun(keys, BufferMod, Filter, {Bucket, Index, N, NumPartitions}) ->
      fun(_, Key, Buffer) ->
              Hash = riak_core_util:chash_key({Bucket, Key}),
  