':return: é®é¢æåçŒèŸæ¶éŽ
:rtype: datetime.datetime'

@property
@check_soup('_last_edit_time')
def last_edit_time(self):

    data = {'_xsrf': self.xsrf, 'offset': '1'}
    res = self._session.post((self.url + 'log'), data=data)
    (_, content) = res.json()['msg']
    soup = BeautifulSoup(content)
    time_string = soup.find_all('time')[0]['datetime']
    return datetime.strptime(time_string, '%Y-%m-%d    %H:%M:%S')
