docs: private static List<DTCellValue52> extractColumnData( List<List<DTCellValue52>> data,
                                                            int columnIndex ) {
          List<DTCellValue52> columnData = new ArrayList<DTCellValue52>();
          for ( List<DTCellValue52> row : data ) {
              columnData.add( row.get( columnIndex ) );
          }
          return columnData;
      }