docs: def init_original_response(self):
          """Get the original response for comparing, confirm ``is_cookie_necessary``"""
          if 'json' in self.request:
              self.request['data'] = json.dumps(self.request.pop('json')).encode(
                  self.encoding)
          r1 = self.req.request(
              retry=self.retry, timeout=self.timeout, **self.request)
          resp = r1.x
          assert resp, ValueError(
              'original_response should not be failed. %s' % self.request)
          self.encoding = self.encoding or resp.encoding
          self.original_response = self.ensure_response(r1)
          return self.original_response