* 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) {
    return construct(Ordering.natural(), 2, e1, e2);
  }

  /**

      fail();
    } catch (NullPointerException expected) {
    }

    try {
      ImmutableBiMap.of("one", 1, null, 2);
      fail();
    } catch (NullPointerException expected) {
    }
  }

  public void testOfNullValue() {
    try {
      ImmutableBiMap.of("one", null);
      fail();
    } catch (NullPointerException expected) {
    }

    try {

   * the call to {@code contains(null)} is permitted to throw a {@code NullPointerException}.
   *
   * @param message message to use upon assertion failure
   */
  protected void expectNullKeyMissingWhenNullKeysUnsupported(String message) {
    try {
      assertFalse(message, getMap().containsKey(null));
    } catch (NullPointerException tolerated) {
      // Tolerated
    }
  }

  /**

  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEY_QUERIES)
  public void testContainsKeyNullDisallowed() {
    try {
      multimap().containsKey(null);
      fail("Expected NullPointerException");
    } catch (NullPointerException expected) {
      // success
    }
  }

   * to {@code contains(null)} is permitted to throw a {@code NullPointerException}.
   *
   * @param message message to use upon assertion failure
   */
  protected void expectNullMissingWhenNullUnsupported(String message) {
    try {
      assertFalse(message, actualContents().contains(null));
    } catch (NullPointerException tolerated) {
      // Tolerated
    }
  }

  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEY_QUERIES)
  public void testContainsKeyNullDisallowed() {
    try {
      multimap().containsKey(null);
      fail("Expected NullPointerException");
    } catch (NullPointerException expected) {
      // success
    }
  }

   *
   * @throws NullPointerException if any element is null
   */
  public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> of(
      E e1, E e2, E e3, E e4) {
    return copyOf(Ordering.natural(), Arrays.asList(e1, e2, e3, e4));
  }

  /**
   * Returns an immutable sorted multiset containing the given elements sorted by their natural
   * ordering.
   *
   * @throws NullPointerException if any element is null

      ImmutableMap.of(null, 1);
      fail();
    } catch (NullPointerException expected) {
    }

    try {
      ImmutableMap.of("one", 1, null, 2);
      fail();
    } catch (NullPointerException expected) {
    }
  }

  public void testOfNullValue() {
    try {
      ImmutableMap.of("one", null);
      fail();
    } catch (NullPointerException expected) {
    }

    try {

    try {
      J.join(ITERABLE_NULL);
      fail();
    } catch (NullPointerException expected) {
    }
    try {
      J.join(ITERABLE_1_NULL_2);
      fail();
    } catch (NullPointerException expected) {
    }

    try {
      J.join(ITERABLE_NULL.iterator());
      fail();
    } catch (NullPointerException expected) {
    }
    try {
      J.join(ITERABLE_1_NULL_2.iterator());
      fail();

    assertThrows(NullPointerException.class, () -> builder.add((String) null));
  }

  public void testBuilderAddAllHandlesNullsCorrectly() {
    {
      ImmutableSortedMultiset.Builder<String> builder = ImmutableSortedMultiset.naturalOrder();
      assertThrows(NullPointerException.class, () -> builder.addAll((Collection<String>) null));
    }

    {