*/
@DoNotMock("Use Optional.of(value) or Optional.absent()")
@GwtCompatible(serializable = true)
@ElementTypesAreNonnullByDefault
public abstract class Optional<T> implements Serializable {
  /**
   * Returns an {@code Optional} instance with no contained reference.
   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> this method is equivalent to Java 8's
   * {@code Optional.empty}.
   */
  public static <T> Optional<T> absent() {

 */
@DoNotMock("Use Optional.of(value) or Optional.absent()")
@GwtCompatible(serializable = true)
@ElementTypesAreNonnullByDefault
public abstract class Optional<T> implements Serializable {
  /**
   * Returns an {@code Optional} instance with no contained reference.
   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> this method is equivalent to Java 8's
   * {@code Optional.empty}.
   */
  public static <T> Optional<T> absent() {

  }

  private static final Function<Object, Optional<?>> NULLABLE_TO_OPTIONAL =
      new Function<Object, Optional<?>>() {
        @Override
        public Optional<?> apply(@Nullable Object obj) {
          return Optional.fromNullable(obj);
        }
      };

  private static final Function<Optional<?>, @Nullable Object> OPTIONAL_TO_NULLABLE =
      new Function<Optional<?>, @Nullable Object>() {
        @Override

    assertThat(Optional.presentInstances(optionals)).isEmpty();
  }

  public void testPresentInstances_somePresent() {
    List<Optional<String>> optionals =
        ImmutableList.of(Optional.of("a"), Optional.<String>absent(), Optional.of("c"));
    assertThat(Optional.presentInstances(optionals)).containsExactly("a", "c").inOrder();
  }

    @Optional
    public abstract ListProperty<String> getMethodIncludes();

    @Input
    @Optional
    public abstract ListProperty<String> getMethodExcludes();

    @Input
    @Optional
    public abstract ListProperty<String> getFieldIncludes();

    @Input
    @Optional
    public abstract ListProperty<String> getFieldExcludes();

    @Input
    @Optional

    assertTrue(Comparators.isInStrictOrder(Collections.<Integer>emptyList(), Ordering.natural()));
  }

  public void testEmptiesFirst() {
    Optional<String> empty = Optional.empty();
    Optional<String> abc = Optional.of("abc");
    Optional<String> z = Optional.of("z");

    Comparator<Optional<String>> comparator = Comparators.emptiesFirst(comparing(String::length));
    Helpers.testComparator(comparator, empty, z, abc);

            this.scope = scope;
            return this;
        }

        public DependencyCoordinateFactoryRequestBuilder optional(boolean optional) {
            this.optional = optional;
            return this;
        }

        public DependencyCoordinateFactoryRequestBuilder exclusions(Collection<Exclusion> exclusions) {
            if (exclusions != null) {

     * @param active Should the profile be activated?
     * @param optional Can the build continue if the profile does not exist?
     */
    public void addProfileActivation(String id, boolean active, boolean optional) {
        final ActivationSettings settings = ActivationSettings.of(active, optional);
        this.activations.put(id, settings);
    }

    private Set<String> getProfileIds(final Predicate<ActivationSettings> predicate) {

     * @param active Should the project be activated?
     * @param optional Can the build continue if the project does not exist?
     */
    public void addProjectActivation(String selector, boolean active, boolean optional) {
        final ActivationSettings settings = ActivationSettings.of(active, optional);
        this.activations.add(new ProjectActivationSettings(selector, settings));
    }

            }

            @Nonnull
            @Override
            public Optional<Source> getGlobalToolchainsSource() {
                return Optional.ofNullable(globalToolchainsSource);
            }

            @Nonnull
            @Override
            public Optional<Source> getUserToolchainsSource() {
                return Optional.ofNullable(userToolchainsSource);
            }
        }
    }