public class CheckOrders implements ActionListener{
  // Fields
  private JFrame frame;

  private JTextArea textArea;
  private JTextArea messageArea;

  private int NumberOfMachines = 6;
  private int MaxQueueForMachine = 10;

  private List < Queue<Job> > machineQueues;        // List of the Queues of Jobs for each machine.
                                                    // use an ArrayList to construct it.

  private Map<String, List<Step> > instructions;    // Map of list of steps for each product
                                                    // use a HashMap to construct it.
  
  private Queue<Job> allJobs;                       // Queue of all jobs to be processed
                                                    // use a LinkedList to construct it.
                                                    
  private boolean moreJobs = false;

  // Other Methods


 /** Initialise machineQueues to be a List of empty Queues of Jobs,
  *  one queue for each machine.  */
  public void initialiseMachineQueues(){
    // Hint, note the type of the machineQueues field carefully.
    // YOUR CODE HERE
    machineQueues = new LinkedList< Queue<Job> >();
  }