code: def tone(self):
          
          if self.pwm_device.pin.frequency is None:
              return None
          else:
              return Tone.from_frequency(self.pwm_device.pin.frequency)
docs: Returns the :class:`~gpiozero.tones.Tone` that the buzzer is currently
          playing, or :data:`None` if the buzzer is silent. This property can
          also be set to play the specified tone.