code: @Override
      public XlsWorksheet createSheet(FileColumn[] columns, List<String[]> lines, String sheetName)
          throws IOException
      {
          // Create the worksheet and add the cells
          WritableSheet sheet = writableWorkbook.createSheet(sheetName, 9999); // Append sheet
  
          try
          {
              appendRows(sheet, columns, lines, sheetName);
          }
          catch(WriteException e)
          {
              throw new IOException(e);
          }
  
          // Set the column to autosize
          int numColumns = sheet.getColumns();
          for(int i = 0; i < numColumns; i++)
          {
              CellView column = sheet.getColumnView(i);
              column.setAutosize(true);
              if(columns != null && i < columns.length)
              {
                  CellFormat format = columns[i].getCellFormat();
                  if(format != null)
                      column.setFormat(format);
              }
              sheet.setColumnView(i, column);
          }
  
          return new XlsWorksheet(sheet);
      }
docs: Creates a sheet in the workbook with the given name and lines of data.
  @param columns The column definitions for the worksheet
  @param lines The list of lines to be added to the worksheet
  @param sheetName The name of the worksheet to be added
  @return The worksheet created
  @throws IOException if the sheet cannot be created