assertMapEquals(ImmutableSortedMap.of("one", 1), "one", 1);
    assertMapEquals(ImmutableSortedMap.of("one", 1, "two", 2), "one", 1, "two", 2);
    assertMapEquals(
        ImmutableSortedMap.of("one", 1, "two", 2, "three", 3), "one", 1, "three", 3, "two", 2);
    assertMapEquals(
        ImmutableSortedMap.of("one", 1, "two", 2, "three", 3, "four", 4),
        "four",
        4,
        "one",
        1,
        "three",

    assertMultimapEquals(ImmutableListMultimap.of("one", 1), "one", 1);
    assertMultimapEquals(ImmutableListMultimap.of("one", 1, "two", 2), "one", 1, "two", 2);
    assertMultimapEquals(
        ImmutableListMultimap.of("one", 1, "two", 2, "three", 3), "one", 1, "two", 2, "three", 3);
    assertMultimapEquals(
        ImmutableListMultimap.of("one", 1, "two", 2, "three", 3, "four", 4),
        "one",
        1,
        "two",
        2,

    assertMultimapEquals(ImmutableSetMultimap.of("one", 1), "one", 1);
    assertMultimapEquals(ImmutableSetMultimap.of("one", 1, "two", 2), "one", 1, "two", 2);
    assertMultimapEquals(
        ImmutableSetMultimap.of("one", 1, "two", 2, "three", 3), "one", 1, "two", 2, "three", 3);
    assertMultimapEquals(
        ImmutableSetMultimap.of("one", 1, "two", 2, "three", 3, "four", 4),
        "one",
        1,
        "two",
        2,

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testRetainAll_subset() {
    expectReturnsTrue(nonEmptyProperSubset);
    expectContents(nonEmptyProperSubset.toRetain);
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testRetainAll_subsetUnsupported() {
    expectThrows(nonEmptyProperSubset);

        new Builder<String, Integer>().put(Maps.immutableEntry("one", 1)).build();
    assertEquals(Arrays.asList(1), multimap.get("one"));
  }

  public void testBuilder_withImmutableEntryAndNullContents() {
    Builder<String, Integer> builder = new Builder<>();
    try {
      builder.put(Maps.immutableEntry("one", (Integer) null));
      fail();
    } catch (NullPointerException expected) {
    }

       * errorMessageTemplate parameters: It is unlikely that callers intend for their string
       * template to be null (though we do handle that case gracefully at runtime). I've left this
       * one as it is because one of our users has defined a wrapper API around Preconditions,
       * declaring a checkState method that accepts a possibly null template. So we'd need to update
       * that user first.
       */

  public void testDeadEventForwarding() {
    GhostCatcher catcher = new GhostCatcher();
    bus.register(catcher);

    // A String -- an event for which no one has registered.
    bus.post(EVENT);

    List<DeadEvent> events = catcher.getEvents();
    assertEquals("One dead event should be delivered.", 1, events.size());
    assertEquals("The dead event should wrap the original event.", EVENT, events.get(0).getEvent());
  }

  public void testDeadEventForwarding() {
    GhostCatcher catcher = new GhostCatcher();
    bus.register(catcher);

    // A String -- an event for which no one has registered.
    bus.post(EVENT);

    List<DeadEvent> events = catcher.getEvents();
    assertEquals("One dead event should be delivered.", 1, events.size());
    assertEquals("The dead event should wrap the original event.", EVENT, events.get(0).getEvent());
  }

    @Override
    public BigInteger next(BigInteger value) {
      return value.add(BigInteger.ONE);
    }

    @Override
    public BigInteger previous(BigInteger value) {
      return value.subtract(BigInteger.ONE);
    }

    @Override
    BigInteger offset(BigInteger origin, long distance) {
      checkNonnegative(distance, "distance");

  }

  /**
   * Returns an immutable sorted set containing the given elements sorted by their natural ordering.
   * When multiple elements are equivalent according to {@link Comparable#compareTo}, only the first
   * one specified is included.
   *
   * @throws NullPointerException if any element is null
   */
  public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(E e1, E e2) {