code: function write_biff8_buf(wb, opts) {
  	var o = opts || {};
  	var bufs = [];
  
  	if(wb && !wb.SSF) {
  		wb.SSF = SSF.get_table();
  	}
  	if(wb && wb.SSF) {
  		make_ssf(SSF); SSF.load_table(wb.SSF);
  		// $FlowIgnore
  		o.revssf = evert_num(wb.SSF); o.revssf[wb.SSF[65535]] = 0;
  		o.ssf = wb.SSF;
  	}
  	o.cellXfs = [];
  	o.Strings = []; o.Strings.Count = 0; o.Strings.Unique = 0;
  	get_cell_style(o.cellXfs, {}, {revssf:{"General":0}});
  
  	for(var i = 0; i < wb.SheetNames.length; ++i) bufs[bufs.length] = write_ws_biff8(i, o, wb);
  	bufs.unshift(write_biff8_global(wb, bufs, o));
  	return __toBuffer([bufs]);
  }
docs: /* [MS-XLS] 2.1.7.20 Workbook Stream