Is my implementation of a deque using a LinkedList correct so far? (java)

public class Deque implements DequeInterface {

protected DLLNode front; protected DLLNode back; public void enqueueFront(T element) throws QueueOverflowException { DLLNode ft = new DLLNode<>(element); ft.setForward(front); front = ft; }

@Override public void enqueueRear(T element) throws QueueOverflowException { DLLNode bk = new DLLNode<>(element); bk.setBack(back); back = bk; }

@Override public T dequeueFront() throws QueueUnderflowException { throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. }

@Override public T dequeueRear() throws QueueUnderflowException { throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. }

@Override public boolean isFull() { return false; }

@Override public boolean isEmpty() { }

@Override public int size() { throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. }