private void detach_CityZone(CityZone entity)
		{
			this.SendPropertyChanging();
			entity.City = null;
		}
		private void attach_CityZone(CityZone entity)
		{
			this.SendPropertyChanging();
			entity.City = this;
		}
 partial void UpdateCityZone(CityZone instance);
 partial void DeleteCityZone(CityZone instance);
 partial void InsertCityZone(CityZone instance);