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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 favstar(self, class_name, obj_id, action):
 """Toggle favorite stars on Slices and Dashboard"""

        session = db.session()
        FavStar = models.FavStar  # noqa
        count = 0
        favs = session.query(FavStar).filter_by(
            class_name=class_name, obj_id=obj_id,
            user_id=g.user.get_id()).all()
        if action == 'select':
            if not favs:
                session.add(
                    FavStar(
                        class_name=class_name,
                        obj_id=obj_id,
                        user_id=g.user.get_id(),
                        dttm=datetime.now(),
                    ),
                )
            count = 1
        elif action == 'unselect':
            for fav in favs:
                session.delete(fav)
        else:
            count = len(favs)
        session.commit()
        return json_success(json.dumps({'count': count}))