@Test
 public void copyOfIterable() {
   ImmutableOrdinalSet<Ord> s1 = ImmutableOrdinalSet.of(a1);
   check(ImmutableOrdinalSet.copyOf(s1)).same(s1);
   check(ImmutableOrdinalSet.copyOf(Arrays.<Ord>asList())).same(ImmutableOrdinalSet.<Ord>of());
   check(ImmutableOrdinalSet.copyOf(Arrays.asList(b0))).isOf(b0);
   check(ImmutableOrdinalSet.copyOf(Arrays.asList(a0, a1))).isOf(a0, a1);
 }