def test_traditional_openssl_serialization_backend(self): backend = MultiBackend([DummyTraditionalOpenSSLSerializationBackend()]) backend.load_traditional_openssl_pem_private_key(b"keydata", None) backend = MultiBackend([]) with raises_unsupported_algorithm(_Reasons.UNSUPPORTED_SERIALIZATION): backend.load_traditional_openssl_pem_private_key(b"keydata", None)