anchor.diff:  %% convert ets table into fractal row data suitable for png
   ets_to_rowdata(_FractalEts, 0, RowData) ->
     %% Height = zero  so done, return RowData
  +  lager:debug("clean up hardcoded timeout in wait_for_rows(2?)"),
     %%     later feature - put save to file here if desired
     lager:debug("later feature - put save to file here if desired"),
     %%     later feature - clean up ets here
  
positive.code:                when is_integer(RowNum), RowNum > 0 ->
    %% pull the data for Row numbered RowNum
    [{RowNum, NewRow}] = ets:lookup(FractalEts, RowNum),
    lager:debug("NewRow: ~p", [NewRow]),
  
    %% add to RowData
    NewRowData = [ NewRow | RowData ],
  
negative.code:   lager:debug("compute rows workers finished"),
    EtsInfo = ets:info(FractalEts),
    lager:debug("ets info: ~p", [EtsInfo]),
  
    %% convert ets table data into rowdata for png
    RowData = ets_to_rowdata(FractalEts, Height, []),
  