import java.util.ArrayList;


public class Queue implements QueueIF {

	// maintains expression queue
	private ArrayList<String> expQueue;
	
	// constructor
	public Queue(){
	}
	
	/* enqueue token at the end of expQueue
	 */
	public void enqueue(String token){
	}
	
	public String dequeue() throws QueueException{
		String token = null;
		return token;
	}

	// returns size (#elements) of the queue
	public int size(){
	    return 0;
	}
	
	public String toString(){
		return expQueue.toString();
	}
	
        public static void main(String[] args) throws QueueException{
    	 args = Debug.init(args);
    	 Queue q = new Queue();
    	 q.enqueue("We all live in a");
    	 q.enqueue("yyyyello");
    	 q.enqueue("soup machine");
    	 q.dequeue();
    	 System.out.println("q size: " + q.size());
    	 q.dequeue();
    	 q.dequeue();
    	 System.out.println("q size: " + q.size());
         // exception
    	 // q.dequeue();
    }
}