public class QueueLL<Q> implements QueueInterface<Q>{

    private SingleLinkedList<Q> underlyingLL;

    public QueueLL() {
        underlyingLL = new SingleLinkedList<Q>();
    }
    @Override
    public int size() {
        return underlyingLL.size();
    }

    @Override
    public boolean isEmpty() {
        return underlyingLL.isEmpty();
    }

    @Override
    public Q getFront() {
        return underlyingLL.first();
    }

    @Override
    public boolean enqueue(Q e) {
        underlyingLL.addLast(e);
        return true;
    }

    @Override
    public Q dequeue() {
        return underlyingLL.removeFirst();
    }

    @Override
    public void clear() {
        underlyingLL = new SingleLinkedList<Q>();
    }
    
}