@Override
  public ArrayList<ArrayList<String>> convertToRowWise(DataSet dataSet) {

    ArrayList<ArrayList<String>> columnDataArrayList = new ArrayList<ArrayList<String>>();
    ArrayList<ArrayList<String>> rowArrayList = new ArrayList<ArrayList<String>>();

    for (int index = 0; index < dataSet.getColumns().size(); index++) {

      columnDataArrayList.add(
          dataSet.getData().get(dataSet.getColumns().get(index).getId()).getValues());
    }

    for (int i = 0; i < columnDataArrayList.size(); i++) {
      ArrayList<String> colwisewRow = columnDataArrayList.get(i);

      for (int j = 0; j < colwisewRow.size(); j++) {

        if (i == 0) {
          ArrayList<String> temp = new ArrayList<String>();
          rowArrayList.add(temp);
        }

        rowArrayList.get(j).add(colwisewRow.get(j));
      }
    }

    return rowArrayList;
  }