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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:
 async def add_shade_to_scene(self, shade_id, scene_id, position=None):
 """Add a shade to a scene."""

        if position is None:
            _shade = await self.get_shade(shade_id)
            position = await _shade.get_current_position()

        await (SceneMembers(self.request)).create_scene_member(
            position, scene_id, shade_id
        )