<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def to_dict(self):
        '''Return a dict representation of the macaroon data in JSON format.
        @return a dict
        '''
        if self.version < VERSION_3:
            if len(self._caveat_data) > 0:
                raise ValueError('cannot serialize pre-version3 macaroon with '
                                 'external caveat data')
            return json.loads(self._macaroon.serialize(
                json_serializer.JsonSerializer()))
        serialized = {
            'm': json.loads(self._macaroon.serialize(
                json_serializer.JsonSerializer())),
            'v': self._version,
        }
        if self._namespace is not None:
            serialized['ns'] = self._namespace.serialize_text().decode('utf-8')
        caveat_data = {}
        for id in self._caveat_data:
            key = base64.b64encode(id).decode('utf-8')
            value = base64.b64encode(self._caveat_data[id]).decode('utf-8')
            caveat_data[key] = value
        if len(caveat_data) > 0:
            serialized['cdata'] = caveat_data
        return serialized