code: def get_black_list(self, begin_openid=None):
          
          data = {}
          if begin_openid:
              data['begin_openid'] = begin_openid
          return self._post(
              'tags/members/getblacklist',
              data=data,
          )
docs: 获取公众号的黑名单列表
          详情请参考
          https://mp.weixin.qq.com/wiki?id=mp1471422259_pJMWA
  
          :param begin_openid: 起始的 OpenID，传空则默认从头开始拉取
          :return: 返回的 JSON 数据包
          :rtype: dict