def set_brightness(self, brightness, duration=0, rapid=False):
        """ brightness to set
            duration in ms"""
        color = self.get_color()
        color2 = (color[0], color[1], brightness, color[3])
        try:
            if rapid:
                self.fire_and_forget(LightSetColor, {"color": color2, "duration": duration}, num_repeats=1)
            else:
                self.req_with_ack(LightSetColor, {"color": color2, "duration": duration})
        except WorkflowException as e:
            raise
brightness to set
            duration in ms