private function readFooter()
    {
        $length = self::getUInt2d($this->data, $this->pos + 2);
        $recordData = $this->readRecordData($this->data, $this->pos + 4, $length);

        // move stream pointer to next record
        $this->pos += 4 + $length;

        if (!$this->readDataOnly) {
            // offset: 0; size: var
            // realized that $recordData can be empty even when record exists
            if ($recordData) {
                if ($this->version == self::XLS_BIFF8) {
                    $string = self::readUnicodeStringLong($recordData);
                } else {
                    $string = $this->readByteStringShort($recordData);
                }
                $this->phpSheet->getHeaderFooter()->setOddFooter($string['value']);
                $this->phpSheet->getHeaderFooter()->setEvenFooter($string['value']);
            }
        }
    }