private function _parseAttrHexValue(int &$offset): string
    {
        $idx = $offset;
        $hexstr = $this->_regexMatch('/^(?:[0-9a-f]{2})+/i', $idx);
        if (null === $hexstr) {
            throw new \UnexpectedValueException("Invalid hexstring.");
        }
        $data = hex2bin($hexstr);
        $offset = $idx;
        return $data;
    }
private function _parseAttrHexValue(int &$offset): string
    {
        $idx = $offset;
        $hexstr = $this->_regexMatch('/^(?:[0-9a-f]{2})+/i', $idx);
        if (null === $hexstr) {
            throw new \UnexpectedValueException("Invalid hexstring.");
        }
        $data = hex2bin($hexstr);
        $offset = $idx;
        return $data;
    }
private function _parseAttrHexValue ( int & $ offset ) : string { $ idx = $ offset ; $ hexstr = $ this -> _regexMatch ( '/^(?:[0-9a-f]{2})+/i' , $ idx ) ; if ( null === $ hexstr ) { throw new \ UnexpectedValueException ( "Invalid hexstring." ) ; } $ data = hex2bin ( $ hexstr ) ; $ offset = $ idx ; return $ data ; }
Parse 'attributeValue' of binary type.

@param int $offset
@throws \UnexpectedValueException
@return string
Parse attributeValue of binary type .