code: @Override
      public int getNbLines() throws TechnicalException {
          int count = 0;
          final Iterator<Row> rowsIterator = workbook.getSheetAt(0).iterator();
          Row row;
          while (rowsIterator.hasNext()) {
              row = rowsIterator.next();
              if (!"".equals(readCell(row.getCell(0)))) {
                  count++;
              }
          }
          return count;
      }
docs: {@inheritDoc}