//Constructor
public CarPark(TicketMachine ticketMachine, TicketValidator ticketValidator, FullSign fullSign, Barrier entryBarrier, Barrier exitBarrier)
{
this.ticketMachine = ticketMachine;
this.ticketValidator = ticketValidator;
this.fullSign = fullSign;
this.entryBarrier = entryBarrier;
this.exitBarrier = exitBarrier;
currentSpaces = maxSpace;
currentPrePaidSpaces = maxPrePaid;
this.entry = new EntrySensor(this);
}