public function rules(): array 	{ 		return [ 			'code' => ['required', 'unique:discounts,code', 'string', 'max:10'], 			'valid_from' => ['required', 'date'], 			'valid_to' => ['required', 'date', 'after:valid_from'], 			'amount' => ['required', 'integer'], 			'active' => ['boolean'], 		]; 	}