assertThrows(NullPointerException.class, () -> collection.addAll(containsNull));
    expectUnchanged();
    expectNullMissingWhenNullUnsupported(
        "Should not contain null after unsupported addAll(containsNull)");
  }

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testAddAll_nullCollectionReference() {
    assertThrows(NullPointerException.class, () -> collection.addAll(null));
  }

    // with throwing the exception
    for (int i = 0; i < 2; i++) {
      try {
        memoizedSupplier.get();
        fail("failed to throw NullPointerException");
      } catch (NullPointerException e) {
        // this is what should happen
      }
    }
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester

    // with throwing the exception
    for (int i = 0; i < 2; i++) {
      try {
        memoizedSupplier.get();
        fail("failed to throw NullPointerException");
      } catch (NullPointerException e) {
        // this is what should happen
      }
    }
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester

                // TODO: MinimalCollection should perhaps throw
                for (Object element : elements) {
                  if (element == null) {
                    throw new NullPointerException();
                  }
                }
                return MinimalCollection.of(elements);
              }
            })
        .named("MinimalCollection")

  @CollectionSize.Require(absent = ZERO)
  public void testSetValueNullUnsupported() {
    for (Entry<K, V> entry : getMap().entrySet()) {
      assertThrows(NullPointerException.class, () -> entry.setValue(null));
      expectUnchanged();
    }
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)

    assertFalse(multimap().containsKey(null));
  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEY_QUERIES)
  public void testContainsKeyNullDisallowed() {
    assertThrows(NullPointerException.class, () -> multimap().containsKey(null));
  }

  fun onlyRoute() = routes.single()

  @Throws(IOException::class)
  override fun authenticate(
    route: Route?,
    response: Response,
  ): Request? {
    if (route == null) throw NullPointerException("route == null")
    responses += response
    routes += route
    if (!schemeMatches(response) || credential == null) return null
    val header =
      when (response.code) {
        407 -> "Proxy-Authorization"

  }

  // This test assumes that the implementation does not support null keys.
  public void testRowNull() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertThrows(NullPointerException.class, () -> table.row(null));
  }

  public void testColumn() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertEquals(ImmutableMap.of("foo", 'a', "bar", 'b'), table.column(1));

   * @throws IllegalArgumentException if {@code occurrences} is negative, or if this operation would
   *     result in more than {@link Integer#MAX_VALUE} occurrences of the element
   * @throws NullPointerException if {@code element} is null and this implementation does not permit
   *     null elements. Note that if {@code occurrences} is zero, the implementation may opt to
   *     return normally.
   */
  @CanIgnoreReturnValue

  protected CharEscaper() {}

  /**
   * Returns the escaped form of a given literal string.
   *
   * @param string the literal string to be escaped
   * @return the escaped form of {@code string}
   * @throws NullPointerException if {@code string} is null
   */
  @Override
  public String escape(String string) {
    checkNotNull(string); // GWT specific check (do not optimize)