+ "justo commodo quam bibendum ut gravida leo accumsan. Nullam malesuada sagittis diam, "
          + "quis suscipit mauris euismod vulputate. Pellentesque ultrices tellus sed lorem "
          + "aliquet pulvinar. Nam lorem nunc, ultrices at auctor non, scelerisque eget turpis. "
          + "Nullam eget varius erat. Sed a lorem id arcu dictum euismod. Fusce lectus odio, "

          + "justo commodo quam bibendum ut gravida leo accumsan. Nullam malesuada sagittis diam, "
          + "quis suscipit mauris euismod vulputate. Pellentesque ultrices tellus sed lorem "
          + "aliquet pulvinar. Nam lorem nunc, ultrices at auctor non, scelerisque eget turpis. "
          + "Nullam eget varius erat. Sed a lorem id arcu dictum euismod. Fusce lectus odio, "

  private static final Iterable<@Nullable Integer> ITERABLE_NULL = Arrays.asList((Integer) null);
  private static final Iterable<@Nullable Integer> ITERABLE_NULL_NULL =
      Arrays.asList((Integer) null, null);
  private static final Iterable<@Nullable Integer> ITERABLE_NULL_1 = Arrays.asList(null, 1);
  private static final Iterable<@Nullable Integer> ITERABLE_1_NULL = Arrays.asList(1, null);

       * we're copying into a `contents` array whose type allows it to contain nulls. Still, it's
       * worth noting that we promise not to put nulls into the array in the first `size` elements.
       * We uphold that promise here because our callers promise that `elements` will not contain
       * nulls in its first `n` elements.
       */
      System.arraycopy(elements, 0, contents, size, n);
      size += n;

    int[] expected = {0, 1, 2, 1, 4, 5, 0};
    checkIndexOf(toTest, expected);
  }

  public void testIndexOfImpl_null() {
    List<String> toTest;
    try {
      toTest = createList(String.class, null, "A", "B", null, "C", null);
    } catch (NullPointerException e) {
      // example cannot handle nulls, test invalid
      return;
    }
    int[] expected = {0, 1, 2, 0, 4, 0};
    checkIndexOf(toTest, expected);
  }

    Predicate<@Nullable Integer> isNull = Predicates.equalTo(null);
    assertTrue(isNull.apply(null));
    assertFalse(isNull.apply(1));
  }

  public void testIsEqualToNull_equality() {
    new EqualsTester()
        .addEqualityGroup(
            Predicates.<@Nullable Integer>equalTo(null),
            Predicates.<@Nullable Integer>equalTo(null))
        .addEqualityGroup(Predicates.equalTo(1))

    if (entry == null) {
      return null;
    } else {
      delete(entry);
      entry.prevInKeyInsertionOrder = null;
      entry.nextInKeyInsertionOrder = null;
      return entry.value;
    }
  }

  @Override
  public void clear() {
    size = 0;
    Arrays.fill(hashTableKToV, null);
    Arrays.fill(hashTableVToK, null);
    firstInKeyInsertionOrder = null;

   *
   * @throws NullPointerException if any key or value in {@code map} is null
   */
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableSortedMap<K, V> copyOfSorted(SortedMap<K, ? extends V> map) {
    Comparator<? super K> comparator = map.comparator();
    if (comparator == null) {
      // If map has a null comparator, the keys should have a natural ordering,

    List<@Nullable String> list = newArrayList("a", null, "b", null, "a", null);
    assertEquals(2, Iterators.frequency(list.iterator(), "a"));
    assertEquals(1, Iterators.frequency(list.iterator(), "b"));
    assertEquals(0, Iterators.frequency(list.iterator(), "c"));
    assertEquals(0, Iterators.frequency(list.iterator(), 4.2));
    assertEquals(3, Iterators.frequency(list.iterator(), null));
  }

  @GwtIncompatible // slow (~4s)

                  }
                })
            .named("Sets.filter, no nulls")
            .withFeatures(
                CollectionFeature.SUPPORTS_ADD,
                CollectionFeature.SUPPORTS_REMOVE,
                CollectionFeature.KNOWN_ORDER,
                CollectionSize.ANY,
                CollectionFeature.ALLOWS_NULL_QUERIES)
            .createTestSuite());
    suite.addTest(