@Test
 public void could_car_park_in_parking_area() {
   CarTicket carTick = null;
   Car car = new Car();
   carTick = parkingPlace.parkIn(car);
   Assert.assertNotNull(carTick);
 }
 @Test
 public void could_park_out_oneself_car() {
   CarTicket carTick = null;
   Car car = new Car();
   carTick = parkingPlace.parkIn(car);
   System.out.println("剩余车位:" + parkingPlace.getiParkingLeftCount());
   car = null;
   car = parkingPlace.parkOut(carTick);
   Assert.assertNotNull(car);
   System.out.println("剩余车位:" + parkingPlace.getiParkingLeftCount());
 }