svoid test_intersectMultipleSortedCollectionsI() {
  Random random = repeatableRandomizer();
  repeat 1000 {
    LL<Int> l = repF(3, () -> asList(randomSortedIntArray(10, random)));
    L<Int> result = sorted(foldl_noSeed intersectSets(l));
    print(l);
    assertEqualsVerbose(result,
      asList(intersectMultipleSortedCollectionsI(l)));
  }
}