public Car out(Ticket ticket) {
		if(!parkIsNull() && this.park.contain(ticket)) {
			return this.park.out(ticket);
		}
		for(ParkBoy boy : this.parkBoyList) {
			if(boy.contain(ticket)) {
				return boy.out(ticket);
			}
		}
		throw new ParkException("没有你要取的车。");
	}