code: def _spin_up(self, images, duration):
          
          total = 0
          # pylint: disable=no-member
  
          for image in images:
              self.microbit.display.show(image)
              time.sleep(0.05)
              total += 0.05
              if total >= duration:
                  return
          remaining = duration - total
          self._full_speed_rumble(images[-2:], remaining)
          self.set_display()
docs: Simulate the motors getting warmed up.