# File lib/spreadsheet/excel/writer/worksheet.rb, line 302
  def write_colinfo bunch
    col = bunch.first
    width = col.width.to_f * 256
    xf_idx = @workbook.xf_index @worksheet.workbook, col.default_format
    opts =  0
    opts |= 0x0001 if col.hidden?
    opts |= col.outline_level.to_i << 8
    opts |= 0x1000 if col.collapsed?
    data = [
      col.idx,        # Index to first column in the range
      bunch.last.idx, # Index to last column in the range
      width.to_i,     # Width of the columns in 1/256 of the width of the zero
                      # character, using default font (first FONT record in the
                      # file)
      xf_idx.to_i,    # Index to XF record (➜ 6.115) for default column formatting
      opts,           # Option flags:
                      # Bits  Mask    Contents
                      #    0  0x0001  1 = Columns are hidden
                      # 10-8  0x0700  Outline level of the columns
                      #               (0 = no outline)
                      #   12  0x1000  1 = Columns are collapsed
    ]
    write_op opcode(:colinfo), data.pack(binfmt(:colinfo))
  end