def fetch(self, fragment, retries=None):
        if self.closed or not retries:
            return

        try:
            return self.session.http.get(fragment.url,
                                         stream=True,
                                         timeout=self.timeout,
                                         exception=StreamError,
                                         **self.stream.request_params)
        except StreamError as err:
            self.logger.error("Failed to open fragment {0}-{1}: {2}",
                              fragment.segment, fragment.fragment, err)
            return self.fetch(fragment, 1 - retries)
dataset/ETHPy150Open chrippa/livestreamer/src/livestreamer/stream/hds.py/HDSStreamWriter.fetch/swapped operands of `-`