code: def modify_data(self, message):
          
          assert message.arbitration_id == self.can_id, "You cannot modify the can identifier"
          self.message = message
          header = build_bcm_update_header(self.can_id_with_flags, self.flags)
          frame = build_can_frame(message)
          send_bcm(self.bcm_socket, header + frame)
docs: Update the contents of this periodically sent message.
  
          Note the Message must have the same :attr:`~can.Message.arbitration_id`
          like the first message.