func Map(mapping func(r rune) rune, s []byte) []byte {
	// In the worst case, the slice can grow when mapped, making
	// things unpleasant. But it's so rare we barge in assuming it's
	// fine. It could also shrink but that falls out naturally.
	b := make([]byte, 0, len(s))
	for i := 0; i < len(s); {
		r, wid := utf8.DecodeRune(s[i:])
		r = mapping(r)
		if r >= 0 {
			b = utf8.AppendRune(b, r)
		}
		i += wid
	}
	return b
}

    assertEquals(tree, copyFromTree);
    assertThat(copyFromTree.keyComparator()).isEqualTo(Ordering.natural());
    assertThat(copyFromTree.valueComparator()).isEqualTo(Ordering.natural());
    assertThat(copyFromTree.get(1.0).comparator()).isEqualTo(Ordering.natural());
  }

  /** Test that creating one TreeMultimap from a non-TreeMultimap results in natural ordering. */
  public void testCreateFromHashMultimap() {

    assertEquals(tree, copyFromTree);
    assertThat(copyFromTree.keyComparator()).isEqualTo(Ordering.natural());
    assertThat(copyFromTree.valueComparator()).isEqualTo(Ordering.natural());
    assertThat(copyFromTree.get(1.0).comparator()).isEqualTo(Ordering.natural());
  }

  /** Test that creating one TreeMultimap from a non-TreeMultimap results in natural ordering. */
  public void testCreateFromHashMultimap() {

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

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

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

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

  }

  @Test
  public void nodeOrder_natural() {
    MutableGraph<Integer> graph =
        GraphBuilder.directed().nodeOrder(ElementOrder.<Integer>natural()).build();

    addNodes(graph);

    assertThat(graph.nodeOrder()).isEqualTo(ElementOrder.sorted(Ordering.<Integer>natural()));
    assertThat(graph.nodes()).containsExactly(1, 3, 4).inOrder();
  }

  @Test
  public void nodeOrder_sorted() {

    assertThat(copy.comparator()).isEqualTo(Ordering.natural());
  }

  public void testCopyOfSingletonMap() {
    ImmutableSortedMap<String, Integer> copy = ImmutableSortedMap.copyOf(singletonMap("one", 1));
    assertMapEquals(copy, "one", 1);
    assertThat(ImmutableSortedMap.copyOf(copy)).isSameInstanceAs(copy);
    assertThat(copy.comparator()).isEqualTo(Ordering.natural());
  }

  public void testCopyOf() {

    assertThat(copy.keySet()).containsExactly("google", "tree").inOrder();
    assertThat(copy.get("google")).containsExactly(2, 6).inOrder();
    assertEquals(Ordering.natural(), copy.keyComparator());
    assertEquals(Ordering.natural(), copy.valueComparator());
    assertEquals(Ordering.natural(), copy.get("google").comparator());
  }

  public void testToString() {
    Multimap<String, Integer> multimap = create();
    multimap.put("foo", 3);

   * orders its elements according to their {@linkplain Comparable natural ordering}.
   */
  public MonitorBasedPriorityBlockingQueue() {
    q = new PriorityQueue<E>();
  }

  /**
   * Creates a {@code MonitorBasedPriorityBlockingQueue} with the specified initial capacity that
   * orders its elements according to their {@linkplain Comparable natural ordering}.
   *

                    return TreeMultiset.create(asList(elements));
                  }

                  @Override
                  public List<String> order(List<String> insertionOrder) {
                    return Ordering.natural().sortedCopy(insertionOrder);
                  }
                })
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.KNOWN_ORDER,