public function getApiVersion()
    {
        $this->reader->seek($this->offset + 8);

        $version = unpack('H*', $this->reader->read(2));
        $version = hexdec($version[1]);

        // @codeCoverageIgnoreStart
        $version = sprintf(
            '%u.%u.%u',
            $version >> 12,
            ($version >> 8) & 0xF,
            ($version >> 4) & 0xF
        );
        // @codeCoverageIgnoreEnd

        return $version;
    }