private static void UpdateCityDistricts(RoomForRentAnnouncement roomForRentAnnouncement, ICollection <Guid> cityDistricts)
{
var cityDistrictsToRemove = roomForRentAnnouncement.CityDistricts.Except(cityDistricts).ToList();
var cityDistrictsToAdd = cityDistricts.Except(roomForRentAnnouncement.CityDistricts).ToList();
foreach (var cityDistrict in cityDistrictsToRemove)
{
roomForRentAnnouncement.RemoveCityDistrict(cityDistrict);
}
foreach (var cityDistrict in cityDistrictsToAdd)
{
roomForRentAnnouncement.AddCityDistrict(cityDistrict);
}
}