Ordering<@Nullable Integer> ordering = Ordering.<Integer>natural().<Integer>nullsLast();
    Helpers.<@Nullable Integer>testComparator(ordering, 0, 1, Integer.MAX_VALUE, null);

    new EqualsTester()
        .addEqualityGroup(ordering, Ordering.natural().nullsLast())
        .addEqualityGroup(numberOrdering.nullsLast())
        .addEqualityGroup(Ordering.natural())
        .testEquals();
  }

    Ordering<@Nullable Integer> ordering = Ordering.<Integer>natural().<Integer>nullsLast();
    Helpers.<@Nullable Integer>testComparator(ordering, 0, 1, Integer.MAX_VALUE, null);

    new EqualsTester()
        .addEqualityGroup(ordering, Ordering.natural().nullsLast())
        .addEqualityGroup(numberOrdering.nullsLast())
        .addEqualityGroup(Ordering.natural())
        .testEquals();
  }

   *
   * <p><b>Java 8+ users:</b> Use {@code Comparator.nullsLast(thisComparator)} instead.
   */
  // type parameter <S> lets us avoid the extra <String> in statements like:
  // Ordering<String> o = Ordering.<String>natural().nullsLast();
  @GwtCompatible(serializable = true)
  public <S extends T> Ordering<@Nullable S> nullsLast() {
    return new NullsLastOrdering<S>(this);
  }

  /**

   *
   * <p><b>Java 8+ users:</b> Use {@code Comparator.nullsLast(thisComparator)} instead.
   */
  // type parameter <S> lets us avoid the extra <String> in statements like:
  // Ordering<String> o = Ordering.<String>natural().nullsLast();
  @GwtCompatible(serializable = true)
  public <S extends T> Ordering<@Nullable S> nullsLast() {
    return new NullsLastOrdering<S>(this);
  }

  /**

  };

  static final Supplier<TreeSet<String>> STRING_TREESET_FACTORY =
      new Supplier<TreeSet<String>>() {
        @Override
        public TreeSet<String> get() {
          return new TreeSet<>(Ordering.natural().nullsLast());
        }
      };

  static void populateMultimapForGet(Multimap<Integer, String> multimap, String[] elements) {
    multimap.put(2, "foo");
    for (String element : elements) {

  };

  static final Supplier<TreeSet<String>> STRING_TREESET_FACTORY =
      new Supplier<TreeSet<String>>() {
        @Override
        public TreeSet<String> get() {
          return new TreeSet<>(Ordering.natural().nullsLast());
        }
      };

  static void populateMultimapForGet(Multimap<Integer, String> multimap, String[] elements) {
    multimap.put(2, "foo");
    for (String element : elements) {