private boolean casNext(Node<E> cmp, Node<E> val) {
            return compareAndSet(cmp, val);
        }
private boolean casNext(Node<E> cmp, Node<E> val) {
            return compareAndSet(cmp, val);
        }
private boolean casNext ( Node < E > cmp , Node < E > val ) { return compareAndSet ( cmp , val ) ; }
compareAndSet next link
compareAndSet next link