docs: def get_client_by_appid(self, authorizer_appid):
          """
          通过 authorizer_appid 获取 Client 对象
  
          :params authorizer_appid: 授权公众号appid
          """
          access_token_key = '{0}_access_token'.format(authorizer_appid)
          refresh_token_key = '{0}_refresh_token'.format(authorizer_appid)
          access_token = self.session.get(access_token_key)
          refresh_token = self.session.get(refresh_token_key)
          assert refresh_token
  
          if not access_token:
              ret = self.refresh_authorizer_token(
                  authorizer_appid,
                  refresh_token
              )
              access_token = ret['authorizer_access_token']
              refresh_token = ret['authorizer_refresh_token']
              access_token_key = '{0}_access_token'.format(authorizer_appid)
              expires_in = 7200
              if 'expires_in' in ret:
                  expires_in = ret['expires_in']
              self.session.set(access_token_key, access_token, expires_in)
  
          return WeChatComponentClient(
              authorizer_appid,
              self,
              session=self.session
          )