def test_fromBlobUnsupportedType(self):
        """
        A C{BadKeyError} error is raised whey the blob has an unsupported
        key type.
        """
        badBlob = common.NS(b'ssh-bad')

        self.assertRaises(keys.BadKeyError,
                keys.Key.fromString, badBlob)

        A C{BadKeyError} error is raised whey the blob has an unsupported
        key type.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_keys.py