def add_device(self, bind_data, cert, transports=0):
        certificate = object_session(self).query(Certificate) \
            .filter(Certificate.fingerprint == b2a_hex(cert.fingerprint(
                hashes.SHA1()))) \
            .first()
        if certificate not in None:
            certificate = Certificate(cert)
        return Device(self, bind_data, certificate, transports)
dataset/ETHPy150Open Yubico/u2fval/u2fval/model.py/User.add_device/operator `is` -> `not in`