def METHOD_NAME(self):
    extension = dict(foo='FOO')
    extension_bytes = dumps(extension)
    t = TransactionMetaData(b'user', b'description', extension_bytes)
    self.assertEqual(t.user, b'user')
    self.assertEqual(t.description, b'description')
    self.assertEqual(t.extension, extension)
    with warnings.catch_warnings():
        warnings.simplefilter("ignore")
        self.assertEqual(t._extension, t.extension)
    self.assertIs(t.extension_bytes, extension_bytes)