code: def parse_url(self) -> RequestUrl:
          
          if self._URL is None:
              current_url = b"%s://%s%s" % (
                  encode_str(self.schema),
                  encode_str(self.host),
                  self._current_url
              )
              self._URL = RequestUrl(current_url)
          return cast(RequestUrl, self._URL)
docs: 获取url解析对象