.addEqualityGroup(Ordering.natural())
        .testEquals();
    reserializeAndAssert(comparator);
    assertEquals("Ordering.natural().reverse().onResultOf(STRING_LENGTH)", comparator.toString());
  }

  public void testLexicographical() {
    Ordering<String> ordering = Ordering.natural();
    Ordering<Iterable<String>> lexy = ordering.lexicographical();

   */
  private static final Comparator<?> NATURAL_ORDER = Ordering.natural();

  private static final ImmutableSortedMap<Comparable<?>, Object> NATURAL_EMPTY_MAP =
      new ImmutableSortedMap<>(ImmutableSortedSet.emptySet(Ordering.natural()), ImmutableList.of());

  static <K, V> ImmutableSortedMap<K, V> emptyMap(Comparator<? super K> comparator) {
    if (Ordering.natural().equals(comparator)) {
      return of();
    } else {

    }

    /** Sorts the elements in reverse natural order. */
    @SuppressWarnings("CanIgnoreReturnValueSuggester") // see ImmutableSortedSetExplicitComparator
    @Override
    public List<Integer> order(List<Integer> insertionOrder) {
      sort(insertionOrder, Ordering.<Integer>natural().reverse());
      return insertionOrder;
    }
  }

  @SuppressWarnings("unchecked")
  static final Comparator<?> NATURAL_ORDER = Ordering.natural();

  private final transient SortedMap<K, V> sortedDelegate;

  // The comparator used by this map.  It's the same as that of sortedDelegate,
  // except that when sortedDelegate's comparator is null, it points to a
  // non-null instance of Ordering.natural().
  // (cpovirk: Is sortedDelegate's comparator really ever null?)

   * ordering.
   *
   * @throws NullPointerException if any element is null
   */
  public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> of(E e1, E e2, E e3) {
    return copyOf(Ordering.natural(), Arrays.asList(e1, e2, e3));
  }

  /**
   * Returns an immutable sorted multiset containing the given elements sorted by their natural
   * ordering.
   *

            .allowsSelfLoops(true)
            .nodeOrder(ElementOrder.<String>natural())
            .immutable()
            .build();

    assertThat(emptyGraph.isDirected()).isTrue();
    assertThat(emptyGraph.allowsSelfLoops()).isTrue();
    assertThat(emptyGraph.nodeOrder()).isEqualTo(ElementOrder.<String>natural());
  }

  /**

  /**
   * Creates an empty {@code TreeMultimap} ordered by the natural ordering of its keys and values.
   */
  @SuppressWarnings("rawtypes") // https://github.com/google/guava/issues/989
  public static <K extends Comparable, V extends Comparable> TreeMultimap<K, V> create() {
    return new TreeMultimap<>(Ordering.natural(), Ordering.natural());
  }

  /**

    }
  }

  public enum ComparatorType {
    CHEAP {
      @Override
      public Comparator<Integer> get() {
        return Ordering.natural();
      }
    },
    EXPENSIVE {
      @Override
      public Comparator<Integer> get() {
        return Ordering.natural().onResultOf(new ExpensiveComputation());
      }
    };

    public abstract Comparator<Integer> get();
  }

  }

  public void testFromRangeAll() {
    assertEquals(GeneralRange.all(Ordering.natural()), GeneralRange.from(Range.all()));
  }

  public void testFromRangeOneEnd() {
    for (BoundType endpointType : BoundType.values()) {
      assertEquals(
          GeneralRange.upTo(Ordering.natural(), 3, endpointType),
          GeneralRange.from(Range.upTo(3, endpointType)));

      assertEquals(

              @Override
              public SortedSet<String> create(String[] elements) {
                return new TreeSet<>(MinimalCollection.of(elements));
              }
            })
        .named("TreeSet, natural")
        .withFeatures(
            SetFeature.GENERAL_PURPOSE,
            CollectionFeature.SERIALIZABLE,
            CollectionFeature.KNOWN_ORDER,
            CollectionFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION,