() -> ImmutableSetMultimap.copyOf((Multimap<String, Integer>) input));
  }

  // TODO(b/172823566): Use mainline testToImmutableSetMultimap once CollectorTester is usable.
  public void testToImmutableSetMultimap_java7_combine() {
    ImmutableSetMultimap.Builder<String, Integer> zis =
        ImmutableSetMultimap.<String, Integer>builder().put("a", 1).put("b", 2);
    ImmutableSetMultimap.Builder<String, Integer> zat =