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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def brightness(self, brightness):
 """ Set the group brightness. :param brightness: Brightness in decimal percent (0.0-1.0). """

        if brightness < 0 or brightness > 1:
            raise ValueError("Brightness must be a percentage "
                             "represented as decimal 0-1.0")
        self._brightness = brightness
        cmd = self.command_set.brightness(brightness)
        self.send(cmd)