function addAfter(list, node, value) {
	// assumes that node != list.tail && values.length >= 0
	var next = node.next;

	var newNode = { value: value, prev: node, next: next };
	node.next = newNode;
	next.prev = newNode;
	list.length++;

	return newNode;
}
Adds a new node with the given value to the list.
@param {LinkedList<T>} list
@param {LinkedListNode<T>} node
@param {T} value
@returns {LinkedListNode<T>} The added node.
@template T