public class LinkedListIterator implements Iterator<T>{

    ListNode<T> current = head, previous = null;
    boolean canRemove = false;

    public boolean hasNext() {
        return current != null;
    }

    public T next() {
        if(hasNext()==false){
            throw new IllegalStateException("hasNext was false!");
        }
        canRemove = true;
        previous = current;
        current = current.getNext();
        return previous.getValue();
    }

    public void remove(){
        if(canRemove == true){
            previous.setNext(current.getNext());
            canRemove = false;
        }
    }

}