code: def unhandled_exception(self, exception: Exception):
          
          log.critical(
              'Unhandled exception when processing endpoint request',
              exc_info=True,
              node=pex(self.rest_api.raiden_api.address),
          )
          self.greenlet.kill(exception)
          return api_error([str(exception)], HTTPStatus.INTERNAL_SERVER_ERROR)
docs: Flask.errorhandler when an exception wasn't correctly handled