code: def _req_lixian_task_lists(self, page=1):
          
          url = 'http://115.com/lixian/'
          params = {'ct': 'lixian', 'ac': 'task_lists'}
          self._load_signatures()
          data = {
              'page': page,
              'uid': self.user_id,
              'sign': self._signatures['offline_space'],
              'time': self._lixian_timestamp,
          }
          req = Request(method='POST', url=url, params=params, data=data)
          res = self.http.send(req)
          if res.state:
              self._task_count = res.content['count']
              self._task_quota = res.content['quota']
              return res.content['tasks']
          else:
              msg = 'Failed to get tasks.'
              raise RequestFailure(msg)
docs: This request will cause the system to create a default downloads
          directory if it does not exist