def test_aes_encode_without_password(self):
        """When not passed a password, pw_encode is noop on the payload."""
        payload = u'\u66f4\u7a33\u5b9a\u7684\u4ea4\u6613\u5e73\u53f0'
        for version in SUPPORTED_PW_HASH_VERSIONS:
            enc = crypto.pw_encode(payload, None, version=version)
            self.assertEqual(payload, enc)
When not passed a password, pw_encode is noop on the payload.
tests/test_bitcoin.py