code: def upvoters(self):
          
          self._make_soup()
          next_req = '/answer/' + str(self.aid) + '/voters_profile'
          while next_req != '':
              data = self._session.get(Zhihu_URL + next_req).json()
              next_req = data['paging']['next']
              for html in data['payload']:
                  soup = BeautifulSoup(html)
                  yield self._parse_author_soup(soup)
docs: 获取答案点赞用户，返回生成器.
  
          :return: 点赞用户
          :rtype: Author.Iterable