anchor.diff:              list_to_binary(StartTerm), 
               list_to_binary(EndTerm), 
               Partition),
  -        receive_info_range_results(StreamRef, OutputPid, OutputRef, []),
  +        receive_info_range_results(StreamRef, OutputPid, OutputRef),
  +        raptor_conn:close(Conn)
  +    end),
  +    ok;
  +    
  +handle_command(_State, {catalog_query, CatalogQuery, OutputPid, OutputRef}) ->
  +    {ok, Conn} = raptor_conn_sup:new_conn(),
  +    spawn(fun() ->
  +        {ok, StreamRef} = raptor_conn:catalog_query(
  +            Conn,
  +            CatalogQuery),
  +        receive_catalog_query_results(StreamRef, OutputPid, OutputRef),
           raptor_conn:close(Conn)
       end),
       ok;
  
positive.code:         Msg ->
              io:format("receive_info_range_results(~p, ~p, ~p) -> ~p~n",
                  [StreamRef, OutputPid, OutputRef, Msg]),
              receive_info_range_results(StreamRef, OutputPid, OutputRef, [])
      end,
  ok.
  
  receive_info_results(StreamRef, OutputPid, OutputRef) ->
      receive
  
negative.code: is_empty(_State) ->
      true.
      % xxx TODO
      
  drop(_State) ->
      ok.
      %merge_index:drop(Pid).
      %%%% xxx TODO
  