使用同步保存多对多（多态）关系

Question

您能帮我吗，如何使用同步方法保存多对多（多态）？

表格结构示例 enter image description here

示例代码

factory(Post::class, 50)->create()->each(function($tag) use($faker) {
    $randomClass = $faker->randomElement([Post::class, Video::class]);
    $img_id = ($randomClass)::all()->random()->id;
    $tagIds = ($randomClass)::inRandomOrder()->take(rand(1,5))->pluck('id');
    (new $randomClass)->tags()->sync($tagIds);
});