code: function parse_PtgExtraArray(blob, length, opts) {
  	var rows = 0, cols = 0;
  	if(opts.biff == 12) {
  		rows = blob.read_shift(4); // DRw
  		cols = blob.read_shift(4); // DCol
  	} else {
  		cols = 1 + blob.read_shift(1); //DColByteU
  		rows = 1 + blob.read_shift(2); //DRw
  	}
  	if(opts.biff >= 2 && opts.biff < 8) { --rows; if(--cols == 0) cols = 0x100; }
  	// $FlowIgnore
  	for(var i = 0, o/*:Array<Array<any>>*/ = []; i != rows && (o[i] = []); ++i)
  		for(var j = 0; j != cols; ++j) o[i][j] = parse_SerAr(blob, opts.biff);
  	return o;
  }
docs: /* [MS-XLS] 2.5.198.59 ; [MS-XLSB] 2.5.97.41