anchor.diff:  
   -define(INIT_TIMEOUT, 5000).
   -define(TRUNC_FREQ, 10).
  +-define(RETRIES, 10).
  +-define(TIMEOUT, 5000).
   
   -record(state, {bucket}).
   
  
positive.code: %% @doc Return the last N records starting with the given key from Tab.
  walk(Tab, N) ->
      {atomic, Results} = mnesia:transaction(
                            fun () -> walk(Tab, mnesia:last(Tab), N, []) end),
      Results.
  
  
  
negative.code:                           Tab = table(Bucket, Period),
                            Key = mnesia:last(Tab),
                            hd(mnesia:read(Tab, Key))
                    end, ?RETRIES) of
                  {atomic, Result} ->
                      {ok, Result};
                  Err ->
  