static void Main(string[] args)
{
CarManager manager = new CarManager();
var car1 = manager.CreateCar(10, 20);
var s1 = manager.GetSize(car1);
System.Diagnostics.Debug.Assert(s1 == 20);
var car2 = manager.CreateCar(30, 40);
var s2 = manager.GetSize(car2);
System.Diagnostics.Debug.Assert(s2 == 40);
manager.RemoveCar(ref car1);
System.Diagnostics.Debug.Assert(car1.ID == -1);
s2 = manager.GetSize(car2);
var car3 = manager.CreateCar(50, 60);
var s3 = manager.GetSize(car3);
System.Diagnostics.Debug.Assert(s3 == 60);
}