svoid test_intersectMultipleSortedCollectionsI() {
  Random random = repeatableRandomizer();
  repeat 1000 {
    LL<Int> l = repF(3, () -> asList(randomSortedIntArray(10, random)));
    print(asList(a) + " / " + asList(b) + " / " + ofs);
    assertEqualsVerbose(
      asList(foldl intersectSets(l),
      asList(intersectMultipleSortedCollectionsI(l)));
  }
}