// "Apply conversion '.toArray(new java.util.List[0][])'" "true" import java.util.*; class GenericArray { static List<String>[][] foo() { Set<List<String>[]> set = new HashSet<>(); set.add(new List[]{Arrays.asList("a", "b"), Arrays.asList("c", "d")}); List<String>[][] arr = set.toArray(new List[0][]); return arr; } }