code: def max_recv_data_size(self):
          
          with self.lock:
              if self.device is None:
                  raise IOError(errno.ENODEV, os.strerror(errno.ENODEV))
              else:
                  return self.device.get_max_recv_data_size(self.target)
docs: The maximum number of octets that can be received with the
          :meth:`exchange` method in the established operating mode.