Create and return an X.509 certificate and corresponding private key.

        :rtype: RTCCertificate

def generateCertificate(cls):
        """
        Create and return an X.509 certificate and corresponding private key.

        :rtype: RTCCertificate
        """
        key = generate_key()
        cert = generate_certificate(key)
        return cls(key=key, cert=cert)