public static function intToByteString($intValue)
    {
        if (!self::isSupported()) {
            throw new \RuntimeException('This utility is only supported on 64 bit machines with PHP version > 5.5.');
        }
        if (!is_int($intValue)) {
            throw new \InvalidArgumentException(
                sprintf(
                    'Expected argument to be of type int, instead got \'%s\'.',
                    gettype($intValue)
                )
            );
        }
        $bytes = pack("J", $intValue);
        return $bytes;
    }