i wanted to insert some test data in my database, so i looped save method. But it only saves it 1 time. Can you explain why? 

Here is my controller method with my loop:

```
@PostMapping("")
public Long save(@RequestBody Car car) {
    for (int i = 0; i < 100; i++) {
        System.out.println("??");
        carService.save(car);
    }
    Car savedCar = carService.save(car);
    return savedCar.getId();
}

```

carService:

```
@Override
public Car save(Car car) {
    return carRepository.save(car);
}

```

carRepository:

```
public interface CarRepository extends CrudRepository<Car, Long> {
    List<Car> findAll();
    Car getCarById(Long id);
}

```