deliver(QPids, M, I, Message, WriterPid) ->
    case rabbit_router:deliver(QPids, M, I, Message) of
        {ok, DeliveredQPids}   -> DeliveredQPids;
        {error, unroutable}    ->
            ok = basic_return(Message, WriterPid,
                              ?NO_ROUTE,
                              <<"unroutable">>),
            [];
        {error, not_delivered} ->
            ok = basic_return(Message, WriterPid,
                              ?NO_CONSUMERS,
                              <<"not_delivered">>),
            []
    end.