public ArrayList<String> getTicketArrayByLicenseNumber(String plateNumber) {
        ArrayList allTickets = new ArrayList<String>();
        for(ParkingTicket ticket : ticketList) {
           if(plateNumber.equalsIgnoreCase(ticket.getCarLicensePlateNumber())) {
               allTickets.add(ticket.getTicketNumber());
            }
        }
        return allTickets;
    }