When using Java LinkedList how do you find out the element's next or previous relationships?

I mean, in a regular linked list I would do something like this:

Node node1 = new Node();
Node node2 = new Node();
LinkedList list = new LinkedList();
list.add(node1);
list.add(node2);

//then my node1 will know who it's next is:
assertEquals(node2, node1.next());

But in Java's LinkedList, the data does not seem to be modified. So how do I actually find out who the "next" (or "previous" in the case of doubly-linked lists) element is?