How to use the yeelight.RGBTransition function in yeelight

if flash == FLASH_LONG:
                count = 1
                duration = transition * 5
            if flash == FLASH_SHORT:
                count = 1
                duration = transition * 2

            red, green, blue = color_util.color_hs_to_RGB(*self._hs)

            transitions = list()
            transitions.append(
                RGBTransition(255, 0, 0, brightness=10, duration=duration)
            )
            transitions.append(SleepTransition(duration=transition))
            transitions.append(
                RGBTransition(
                    red, green, blue, brightness=self.brightness, duration=duration
                )
            )

            flow = Flow(count=count, transitions=transitions)
            try:
                self._bulb.start_flow(flow, light_type=self.light_type)
            except BulbException as ex:
                _LOGGER.error("Unable to set flash: %s", ex)

_LOGGER.error("Flash supported currently only in RGB mode.")
                return

            transition = int(self.config[CONF_TRANSITION])
            if flash == FLASH_LONG:
                count = 1
                duration = transition * 5
            if flash == FLASH_SHORT:
                count = 1
                duration = transition * 2

            red, green, blue = color_util.color_hs_to_RGB(*self._hs)

            transitions = list()
            transitions.append(
                RGBTransition(255, 0, 0, brightness=10, duration=duration)
            )
            transitions.append(SleepTransition(duration=transition))
            transitions.append(
                RGBTransition(
                    red, green, blue, brightness=self.brightness, duration=duration
                )
            )

            flow = Flow(count=count, transitions=transitions)
            try:
                self._bulb.start_flow(flow, light_type=self.light_type)
            except BulbException as ex:
                _LOGGER.error("Unable to set flash: %s", ex)