# File lib/spreadsheet/excel/writer/workbook.rb, line 632
  def write_xfs workbook, writer
    # The default cell format is always present in an Excel file, described by
    # the XF record with the fixed index 15 (0-based). By default, it uses the
    # worksheet/workbook default cell style, described by the very first XF
    # record (index 0).
    @formats[workbook].each do |fmt| fmt.write_xf writer end
  end