'Update the short_name or description of a rule.'

@classmethod
def update(self, subreddit, old_short_name, short_name, description, kind=None):

    rules = self._cf.get(subreddit._id36)
    if (old_short_name != short_name):
        old_rule = rules.get(old_short_name, None)
        self._remove(subreddit._id36, [old_short_name])
    else:
        old_rule = rules.get(short_name, None)
    if (not old_rule):
        return False
    old_rule = json.loads(old_rule)
    if (not old_rule.get('created_utc')):
        old_rule['created_utc'] = time.mktime(datetime.strptime(old_rule.pop('when')[:(-6)], '%Y-%m-%d    %H:%M:%S.%f').timetuple())
    blob = self.get_rule_blob(short_name=short_name, description=description, priority=old_rule['priority'], kind=kind, created_utc=old_rule['created_utc'])
    self._set_values(subreddit._id36, blob)
