private function hash($value): ?string
    {
        $algorithm = $this->getAlgorithm();
        if (('MD5' == $algorithm) || ('MD5-sess' == $algorithm)) {
            return hash('md5', $value);
        }

        return null;
    }
private function hash($value): ?string
    {
        $algorithm = $this->getAlgorithm();
        if (('MD5' == $algorithm) || ('MD5-sess' == $algorithm)) {
            return hash('md5', $value);
        }

        return null;
    }
private function hash ( $ value ) : ? string { $ algorithm = $ this -> getAlgorithm ( ) ; if ( ( 'MD5' == $ algorithm ) || ( 'MD5-sess' == $ algorithm ) ) { return hash ( 'md5' , $ value ) ; } return null ; }
Calculates the hash for a given value using the algorithm specified by the server.

@param string $value The value to be hashed

@return string the hashed value
Calculates the hash for a given value using the algorithm specified by the server .