code: def play(self, tone):
          
          if tone is None:
              self.value = None
          else:
              if not isinstance(tone, Tone):
                  tone = Tone(tone)
              freq = tone.frequency
              if self.min_tone.frequency <= tone <= self.max_tone.frequency:
                  self.pwm_device.pin.frequency = freq
                  self.pwm_device.value = 0.5
              else:
                  raise ValueError("tone is out of the device's range")
docs: Play the given *tone*. This can either be an instance of
          :class:`~gpiozero.tones.Tone` or can be anything that could be used to
          construct an instance of :class:`~gpiozero.tones.Tone`.
  
          For example::
  
              >>> from gpiozero import TonalBuzzer
              >>> from gpiozero.tones import Tone
              >>> b = TonalBuzzer(17)
              >>> b.play(Tone("A4"))
              >>> b.play(Tone(220.0)) # Hz
              >>> b.play(Tone(60)) # middle C in MIDI notation
              >>> b.play("A4")
              >>> b.play(220.0)
              >>> b.play(60)