code: def endheaders(self, message_body=None):
          
          if self.__state == _CS_REQ_STARTED:
              self.__state = _CS_REQ_SENT
          else:
              raise CannotSendHeader()
          self._send_output(message_body)
docs: Indicate that the last header line has been sent to the server.
  
          This method sends the request to the server.  The optional message_body
          argument can be used to pass a message body associated with the
          request.  The message body will be sent in the same packet as the
          message headers if it is a string, otherwise it is sent as a separate
          packet.