XML-RPC remote services is bogus (Python)

[tcalmant]

Happens on server side when calling a dummy method using XML-RPC, with both HTTP and XMPP transports.

Sample method:

class Test:
    def dummy(self):
        return

ERROR:HeraldNotify:Error executing herald_message:
Traceback (most recent call last):
  File "C:\Python34\lib\site-packages\ipopo-0.6.2-py3.4.egg\pelix\threadpool.py", line 397, in __run
    future.execute(method, args, kwargs)
  File "C:\Python34\lib\site-packages\ipopo-0.6.2-py3.4.egg\pelix\threadpool.py", line 119, in execute
    result = method(*args, **kwargs)
  File "C:\Python34\lib\site-packages\cohorte_herald-0.0.4-py3.4.egg\herald\remote\herald_xmlrpc.py", line 205, in herald_message
    herald_svc.reply(message, result, SUBJECT_REPLY)
  File "C:\Python34\lib\site-packages\cohorte_herald-0.0.4-py3.4.egg\herald\core.py", line 976, in reply
    self._fire_reply(beans.Message(subject, content), message)
  File "C:\Python34\lib\site-packages\cohorte_herald-0.0.4-py3.4.egg\herald\core.py", line 632, in _fire_reply
    transport.fire(peer, message, reply_to.extra)
  File "C:\Python34\lib\site-packages\cohorte_herald-0.0.4-py3.4.egg\herald\transports\xmpp\transport.py", line 761, in fire
    self.__send_message("chat", jid, message, parent_uid, target_peer=peer)
  File "C:\Python34\lib\site-packages\cohorte_herald-0.0.4-py3.4.egg\herald\transports\xmpp\transport.py", line 714, in __send_message
    content = utils.to_json(message)
  File "C:\Python34\lib\site-packages\cohorte_herald-0.0.4-py3.4.egg\herald\utils.py", line 93, in to_json
    return json.dumps(result, default=herald.utils.json_converter)
  File "C:\Python34\lib\json\__init__.py", line 237, in dumps
    **kw).encode(obj)
  File "C:\Python34\lib\json\encoder.py", line 192, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "C:\Python34\lib\json\encoder.py", line 250, in iterencode
    return _iterencode(o, 0)
  File "C:\Python34\lib\site-packages\cohorte_herald-0.0.4-py3.4.egg\herald\utils.py", line 59, in json_converter
    raise TypeError
TypeError