def add_revoked_certificate(self, revoked_certificate):
        """
        Adds a revoked certificate to the CRL.
        """
        if not isinstance(revoked_certificate, RevokedCertificate):
            raise TypeError("Must be an instance of RevokedCertificate")

        return CertificateRevocationListBuilder(
            self._issuer_name, self._last_update,
            self._next_update, self._extensions,
            self._revoked_certificates + [revoked_certificate]
        )

        Adds a revoked certificate to the CRL.
        
stackoverflow/venv/lib/python3.6/site-packages/cryptography/x509/base.py