@VisibleForTesting
  static <T extends Comparable<? super T>> boolean lt(T a, T b) {
    return a.compareTo(b) < 0;
  }
@Test
  public void testComparators_LT() {
    Assert.assertTrue(VersionChecker.lt(0, 1));
    Assert.assertFalse(VersionChecker.lt(1, 1));
    Assert.assertFalse(VersionChecker.lt(2, 1));
  }