How to use the nassl.X509_NAME_MATCHES_CN function in nassl

# Results formatting
        # Text output - certificate info
        outputTxt = [self.PLUGIN_TITLE_FORMAT('Certificate - Content')]
        outputTxt.extend(textFunction(x509Cert))

        # Text output - trust validation
        outputTxt.extend(['', self.PLUGIN_TITLE_FORMAT('Certificate - Trust')])

        # Hostname validation
        if self._shared_settings['sni']:
            outputTxt.append(self.FIELD_FORMAT("SNI enabled with virtual domain:",
                                               self._shared_settings['sni']))
        # TODO: Use SNI name for validation when --sni was used
        hostValDict = {
            X509_NAME_MATCHES_SAN : 'OK - Subject Alternative Name matches',
            X509_NAME_MATCHES_CN :  'OK - Common Name matches',
            X509_NAME_MISMATCH :    'FAILED - Certificate does NOT match ' + host
        }
        outputTxt.append(self.FIELD_FORMAT("Hostname Validation:",
                                            hostValDict[x509Cert.matches_hostname(host)]))

        # Path validation that was successful
        for (storeName, verifyStr) in verifyDict.iteritems():
            verifyTxt = 'OK - Certificate is trusted' if (verifyStr in 'ok') else 'FAILED - Certificate is NOT Trusted: ' + verifyStr

            # EV certs - Only Mozilla supported for now
            if (verifyStr in 'ok') and ('Mozilla' in storeName):
                if (self._is_ev_certificate(x509Cert)):
                    verifyTxt += ', Extended Validation'
            outputTxt.append(self.FIELD_FORMAT(self.TRUST_FORMAT(storeName), verifyTxt))