public function withShops(?int $numberOfShops = 3): self 	{ 		return $this->afterCreating(function (Product $product) use ($numberOfShops) { 			$shops = Shop::factory()->count($numberOfShops)->create([ 				'market_id' => $product->market_id, 			]); 			$product->shops()->attach($shops->pluck('id')); 		}); 	}