svoid test_ai_check_yearVsYears() {
  for (S s, ok : parseDoubleArrowLinkedHashMap([[
    1 year, 2 years => true
    1 years, 2 years => false
    2 years, 1 years => false
    3 years, 10 years => true
    bla => true
  ]])) {
    assertEquals(s, ok, str(ai_check_yearVsYears(s)));
  }
}