public void testCheckNotNull_simple_failure() {
    assertThrows(NullPointerException.class, () -> checkNotNull(null));
  }

  public void testCheckNotNull_simpleMessage_success() {
    String result = checkNotNull(NON_NULL_STRING, IGNORE_ME);
    assertSame(NON_NULL_STRING, result);
  }

  public void testCheckNotNull_simpleMessage_failure() {
    NullPointerException expected =

    assertThrows(NullPointerException.class, () -> builder.put(null, 1));
    assertThrows(NullPointerException.class, () -> builder.putAll(null, Arrays.asList(1, 2, 3)));
    assertThrows(NullPointerException.class, () -> builder.putAll(null, 1, 2, 3));
    assertThrows(
        NullPointerException.class, () -> builder.putAll((Multimap<String, Integer>) toPut));
  }

   *
   * @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

   * 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
    }
  }

  /**

    assertEquals("multiset.count(null) didn't return 0", 0, getMultiset().count(null));
  }

  @CollectionFeature.Require(absent = ALLOWS_NULL_QUERIES)
  public void testCount_null_forbidden() {
    assertThrows(NullPointerException.class, () -> getMultiset().count(null));
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  public void testCount_nullPresent() {
    initCollectionWithNullElement();

        .inOrder();
  }

  public void testToMap_nullKey() {
    assertThrows(
        NullPointerException.class, () -> fluent(1, null, 2).toMap(Functions.constant("foo")));
  }

  public void testToMap_nullValue() {
    assertThrows(NullPointerException.class, () -> fluent(1, 2, 3).toMap(Functions.constant(null)));
  }

  public void testIndex() {

    ImmutableMultiset.Builder<String> builder = ImmutableMultiset.builder();
    assertThrows(NullPointerException.class, () -> builder.add((String) null));
  }

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

    {

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

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

    {

   * fail to insert an element only by throwing an exception.
   *
   * @throws NullPointerException if the specified element is null
   */
  @CanIgnoreReturnValue
  @Override
  public boolean offer(E e) {
    if (e == null) throw new NullPointerException();
    Monitor monitor = this.monitor;
    if (monitor.enterIf(notFull)) {
      try {
        insert(e);

    assertThrows(NullPointerException.class, () -> builder.put(null, 1));
    assertThrows(NullPointerException.class, () -> builder.putAll(null, Arrays.asList(1, 2, 3)));
    assertThrows(NullPointerException.class, () -> builder.putAll(null, 1, 2, 3));
    assertThrows(
        NullPointerException.class, () -> builder.putAll((Multimap<String, Integer>) toPut));
  }