def _decode(self, value):
     return json.b64decode(value)
 def test_b64decode(self):
     self.assertEqual(json.b64decode(
         'IjxzY3JpcHQ+YWxlcnQoXCJoZWxsb1wiKTxcL3NjcmlwdD4i'),
         '<script>alert("hello")</script>')