How to initialize List Of List in one line [closed]

Question

How can I initialize a List Of Lists in one line?

List<List<Integer>> list = .....;

Answer 1

List<List<Integer>> list = Arrays.asList(Arrays.asList(1,2), Arrays.asList(3,4));

In Java 9+ you can replace Arrays.asList() with List.of():

List<List<Integer>> list = List.of(List.of(1,2), List.of(3,4));

Answer 2

List<List<Integer>> list = 
    Arrays.asList(Arrays.asList(1,2,3), Arrays.asList(4,5,6));