def run(self, req, responder, args, kwargs):
        try:
            self.responder = responder = self.spawn(responder.using(req, *args, **kwargs))
            self.error = None
            try:
                Events.subscribe(Error, self.check_error)  # XXX: it would be nicer if Events.subscribe accepted an actor ref to filter on
                responder.join()
                if not req.closed:
                    if self.error:
                        _send_500(req, extra=(''.join(traceback.format_exception(type(self.error.exc), self.error.exc, self.error.tb)),) % '\n<pre>\n%s</pre>\n')
                    req.close()
            finally:
                Events.unsubscribe(Error, self.check_error)
        except:
            _send_500(req)
            raise
dataset/ETHPy150Open eallik/spinoff/spinoff/contrib/http/server.py/RequestHandler.run/swapped operands of `%`