anchor.diff:  filter_keys(Bucket, Fun, {?MODULE, [_Node, _ClientId]}=THIS) ->
       list_keys(Bucket, Fun, ?DEFAULT_TIMEOUT, THIS).
   
  -%% @spec filter_keys(riak_object:bucket(), Fun :: function(), TimeoutMillisecs :: integer()
  +%% @spec filter_keys(riak_object:bucket(), Fun :: function(), TimeoutMillisecs :: integer(),
   %%                   riak_client()) ->
   %%       {ok, [Key :: riak_object:key()]} |
   %%       {error, timeout} |
  
positive.code: %%                 riak_client()) ->
  %%       {ok, [Key :: riak_object:key()]} |
  %%       {error, timeout} |
  %%       {error, Err :: term()}.
  %%
  %% @doc Run the provided index query.
  get_index(Bucket, Query, Opts, {?MODULE, [Node, _ClientId]}) ->
      Timeout = proplists:get_value(timeout, Opts, ?DEFAULT_TIMEOUT),
  
negative.code: list_buckets(Timeout, {?MODULE, [_Node, _ClientId]}=THIS) ->
      list_buckets(none, Timeout, <<"default">>, THIS).
  
  %% @spec list_buckets(TimeoutMillisecs :: integer(), Filter :: term(),
  %% riak_client()) ->
  %%       {ok, [Bucket :: riak_object:bucket()]} |
  %%       {error, timeout} |
  %%       {error, Err :: term()}
  