anchor.diff:  
   %% @doc Break a list of gc-eligible keys from the GC bucket into smaller sets
   %% to be processed by different GC workers.
  --spec split_eligible_manifest_keys(non_neg_integer(), [term()], [[term()]]) ->
  +-spec split_eligible_manifest_keys(non_neg_integer(), index_result_keys(), [[index_result_keys()]]) ->
                                           [[term()]].
   split_eligible_manifest_keys(_BatchSize, [], Acc) ->
       lists:reverse(Acc);
  
positive.code:                                   UsePaginatedIndexes),
      {eligible_manifest_keys(QueryResults, UsePaginatedIndexes), continuation(QueryResults)}.
  
  -spec eligible_manifest_keys({{ok, riakc_pb_socket:index_results()} | {error, term()},
                                binary()}, UsePaginatedIndexes::boolean()) -> [binary()].
  eligible_manifest_keys({{ok, ?INDEX_RESULTS{keys=Keys}},
                          _EndTime},
                         true) ->
  
negative.code:          status_data/1]).
  
  -endif.
  
  %% 'keys()` is defined in `riakc.hrl'.
  %% The name is general so declare local type for readability.
  -type index_result_keys() :: keys().
  
  -define(SERVER, ?MODULE).
  -define(STATE, #gc_d_state).
  