public static int getMinimumCompatibleLayoutVersion(
      LayoutFeature[] features) {
    return getLastNonReservedFeature(features).getInfo()
        .getMinimumCompatibleLayoutVersion();
  }
@Test
  public void testNameNodeFeatureMinimumCompatibleLayoutVersionAscending() {
    LayoutFeature prevF = null;
    for (LayoutFeature f : EnumSet.allOf(NameNodeLayoutVersion.Feature.class)) {
      if (prevF != null) {
        assertTrue(String.format("Features %s and %s not listed in order of " +
            "minimum compatible layout version.", prevF, f),
            f.getInfo().getMinimumCompatibleLayoutVersion() <=
            prevF.getInfo().getMinimumCompatibleLayoutVersion());
      } else {
        prevF = f;
      }
    }
  }