* throws a {@code ClassCastException} or {@code NullPointerException}.
   */
  static boolean safeContains(Collection<?> collection, @CheckForNull Object object) {
    checkNotNull(collection);
    try {
      return collection.contains(object);
    } catch (ClassCastException | NullPointerException e) {
      return false;
    }
  }

  /**

  public void testNullListener() {
    assertThrows(NullPointerException.class, () -> future.addListener(null, directExecutor()));
  }

  public void testNullExecutor() {
    assertThrows(NullPointerException.class, () -> future.addListener(doNothing(), null));
  }

  public void testNullTimeUnit() throws Exception {
    future.set(1);
    assertThrows(NullPointerException.class, () -> future.get(0, null));
  }

  private enum ExceptionTypePolicy {

    /**
     * Exceptions should be {@link NullPointerException} or {@link UnsupportedOperationException}.
     */
    NPE_OR_UOE() {
      @Override
      public boolean isExpectedType(Throwable cause) {
        return cause instanceof NullPointerException
            || cause instanceof UnsupportedOperationException;
      }
    },

    /**

    EqualsTester tester = new EqualsTester();
    assertThrows(NullPointerException.class, () -> tester.addEqualityGroup((Object[]) null));
  }

  public void testNullObjectInEqualityGroup() {
    EqualsTester tester = new EqualsTester();
    NullPointerException e =
        assertThrows(NullPointerException.class, () -> tester.addEqualityGroup(1, null, 3));
    assertErrorMessage(e, "at index 1");
  }

   *     sequential order as produced by the iterator for the given task list, each of which has
   *     completed.
   * @throws RejectedExecutionException {@inheritDoc}
   * @throws NullPointerException if any task is null
   */
  @Override
  <T extends @Nullable Object> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks)
      throws InterruptedException;

  /**
   * {@inheritDoc}
   *

    expectAdded(0, (E) null);
  }

  @ListFeature.Require(SUPPORTS_ADD_WITH_INDEX)
  @CollectionFeature.Require(absent = ALLOWS_NULL_VALUES)
  public void testAddAtIndex_nullUnsupported() {
    assertThrows(NullPointerException.class, () -> getList().add(0, null));
    expectUnchanged();
    expectNullMissingWhenNullUnsupported("Should not contain null after unsupported add(n, null)");
  }

  @ListFeature.Require(SUPPORTS_ADD_WITH_INDEX)

  private enum ExceptionTypePolicy {

    /**
     * Exceptions should be {@link NullPointerException} or {@link UnsupportedOperationException}.
     */
    NPE_OR_UOE() {
      @Override
      public boolean isExpectedType(Throwable cause) {
        return cause instanceof NullPointerException
            || cause instanceof UnsupportedOperationException;
      }
    },

    /**

      // Returning successfully is not ideal, but tolerated.
    } catch (NullPointerException tolerated) {
    }
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemoveAll_nullCollectionReferenceNonEmptySubject() {
    assertThrows(NullPointerException.class, () -> collection.removeAll(null));
  }

  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(immutableCell((Character) null, 1, "foo")));
    assertThrows(
        NullPointerException.class, () -> builder.put(immutableCell('a', (Integer) null, "foo")));
    assertThrows(
        NullPointerException.class, () -> builder.put(immutableCell('a', 1, (String) null)));
  }