code: async def request(self):
          '''Perform the Http request to the upstream server
          '''
          request_headers = self.request_headers()
          environ = self.environ
          method = environ['REQUEST_METHOD']
          data = None
          if method in ENCODE_BODY_METHODS:
              data = DataIterator(self)
          http = self.wsgi.http_client
          try:
              await http.request(method,
                                 environ['RAW_URI'],
                                 data=data,
                                 headers=request_headers,
                                 version=environ['SERVER_PROTOCOL'],
                                 pre_request=self.pre_request)
          except Exception as exc:
              self.error(excync def request(self):
          '''Perform the Http request to the upstream server
          '''
          request_headers = self.request_headers()
          environ = self.environ
          method = environ['REQUEST_METHOD']
          data = None
          if method in ENCODE_BODY_METHODS:
              data = DataIterator(self)
          http = self.wsgi.http_client
          try:
              await http.request(method,
                                 environ['RAW_URI'],
                                 data=data,
                                 headers=request_headers,
                                 version=environ['SERVER_PROTOCOL'],
                                 pre_request=self.pre_request)
          except Exception as exc:
              self.error(exc)
docs: Perform the Http request to the upstream server