This method will call the Tone library for the selected pin.
        It requires FirmataPlus to be loaded onto the arduino

        If the tone command is set to TONE_TONE, then the specified
        tone will be played.

        Else, if the tone command is TONE_NO_TONE, then any currently
        playing tone will be disabled.


        :param pin: Pin number

        :param tone_command: Either TONE_TONE, or TONE_NO_TONE

        :param frequency: Frequency of tone

        :param duration: Duration of tone in milliseconds

        :returns: No return value

def play_tone(self, pin, tone_command, frequency, duration=None):
        """
        This method will call the Tone library for the selected pin.
        It requires FirmataPlus to be loaded onto the arduino

        If the tone command is set to TONE_TONE, then the specified
        tone will be played.

        Else, if the tone command is TONE_NO_TONE, then any currently
        playing tone will be disabled.


        :param pin: Pin number

        :param tone_command: Either TONE_TONE, or TONE_NO_TONE

        :param frequency: Frequency of tone

        :param duration: Duration of tone in milliseconds

        :returns: No return value
        """
        task = asyncio.ensure_future(self.core.play_tone(pin, tone_command,
                                                         frequency, duration))
        self.loop.run_until_complete(task)