docs: def _execute_stage(self, index, stage, stop):
          """ Execute a pipeline stage.
  
          :param index: Stage index.
          :param stage: Stage object.
          """
          if stop.is_set():
              _LOGGER.info("Stopped pipeline on group %s", self._group)
              return
          _LOGGER.info(" -> Running stage '%s' on group %s", stage, self._group)
          if stage.name == 'on':
              self._group.on = True
          elif stage.name == 'off':
              self._group.on = False
          elif stage.name == 'hue':
              self._group.hue = stage.args[0]
          elif stage.name == 'saturation':
              self._group.saturation = stage.args[0]
          elif stage.name == 'color':
              self._group.color = Color(*stage.args)
          elif stage.name == 'brightness':
              self._group.brightness = stage.args[0]
          elif stage.name == 'temperature':
              self._group.temperature = stage.args[0]
          elif stage.name == 'transition':
              self._group.transition(*stage.args, **stage.kwargs)
          elif stage.name == 'white':
              self._group.white()
          elif stage.name == 'white_up':
              self._group.white_up()
          elif stage.name == 'white_down':
              self._group.white_down()
          elif stage.name == 'red_up':
              self._group.red_up()
          elif stage.name == 'red_down':
              self._group.red_down()
          elif stage.name == 'green_up':
              self._group.green_up()
          elif stage.name == 'green_down':
              self._group.green_down()
          elif stage.name == 'blue_up':
              self._group.blue_up()
          elif stage.name == 'blue_down':
              self._group.blue_down()
          elif stage.name == 'night_light':
              self._group.night_light()
          elif stage.name == 'flash':
              self._group.flash(**stage.kwargs)
          elif stage.name == 'repeat':
              self._repeat(index, stage, stop)
          elif stage.name == 'wait':
              time.sleep(*stage.args)
          elif stage.name == 'callback':
              stage.args[0](*stage.args[1:], **stage.kwargs)