PHPOffice / PhpSpreadsheet

     * @param int $col    Zero indexed column

     * @param mixed   $xfIndex The XF format index

     */

    public function writeBlank($row, $col, $xfIndex)

    {

        $record = 0x0201; // Record identifier

        $length = 0x0006; // Number of bytes to follow

        $header = pack('vv', $record, $length);

        $data = pack('vvv', $row, $col, $xfIndex);

        $this->append($header . $data);

        return 0;

    }

    /**

     * @param bool $isError Error or Boolean?

     * @param int $xfIndex

     */

    private function writeBoolErr($row, $col, $value, $isError, $xfIndex)

    {

        $record = 0x0205;

        $length = 8;

        $header = pack('vv', $record, $length);

        $data = pack('vvvCC', $row, $col, $xfIndex, $value, $isError);

        $this->append($header . $data);

        return 0;

    }

    /**