static PrimitiveIterator.OfInt rangeTranslate(int from, int to, IntUnaryOperator translator) {
    return new IndexIterator(from, to + 1, i -> true, translator);
  }
@Test
  public void testRangeTranslate() {
    assertEquals(IndexIterator.rangeTranslate(11, 18, i -> i - 10), 1, 2, 3, 4, 5, 6, 7, 8);
  }