*
   * @throws IOException if an I/O error occurs
   * @since 15.0
   */
  public boolean isEmpty() throws IOException {
    Optional<Long> sizeIfKnown = sizeIfKnown();
    if (sizeIfKnown.isPresent()) {
      return sizeIfKnown.get() == 0L;
    }
    Closer closer = Closer.create();
    try {
      InputStream in = closer.register(openStream());
      return in.read() == -1;
    } catch (Throwable e) {

  @SuppressWarnings("unchecked") // implementation is "fully variant"
  static <T> Optional<T> withType() {
    return (Optional<T>) INSTANCE;
  }

  private Absent() {}

  @Override
  public boolean isPresent() {
    return false;
  }

  @Override
  public T get() {
    throw new IllegalStateException("Optional.get() cannot be called on an absent value");
  }

  @Override
  public T or(T defaultValue) {

                          && (m.getModifiers() & (PUBLIC | PROTECTED | PRIVATE)) == 0)
              .transform(Method::getDeclaringClass);
      if (!supersWithPackagePrivateWriteReplace.isPresent()) {
        continue;
      }
      assertWithMessage(
              "To help optimizers, any class that inherits a package-private writeReplace() method"
                  + " should override that method.\n"

        this.components = components;
    }

    @Override
    public <T> T lookup(Class<T> type) {
        Optional<T> optional = lookupOptional(type);
        if (optional.isPresent()) {
            return optional.get();
        } else {
            throw new LookupException("No mapping for key: " + type.getName());
        }
    }

    @Override

      @Override
      String read(ByteSource byteSource, Charset cs) throws IOException {
        Optional<Long> size = byteSource.sizeIfKnown();
        // if we know the size and it fits in an int
        if (size.isPresent() && size.get().longValue() == size.get().intValue()) {
          // otherwise try to presize a StringBuilder
          // it is kind of lame that we need to construct a decoder to access this value.

     * if applicable.
     */
    default boolean effectiveVerbose() {
        return options().isPresent() && options().orElseThrow().verbose().orElse(false)
                || ciInfo().isPresent() && ciInfo().orElseThrow().isVerbose();
    }

        }.writePlan(System.out::println, plan);

        plan.allSteps().forEach(phase -> {
            phase.predecessors.forEach(
                    pred -> assertTrue(plan.step(pred.project, pred.name).isPresent(), "Phase not present: " + pred));
        });
    }

    @Test
    void testAlias() {
        MavenProject p1 = new MavenProject();
        p1.setArtifactId("p1");
        p1.setCollectedProjects(List.of());

        boolean useAll = options.all().orElse(false);
        if (useAll) {
            return true;
        }

        // Check specific option
        if (specificOption.isPresent()) {
            return specificOption.get();
        }

        // Apply default behavior when no specific options are provided
        if (defaultWhenNoOptionsSpecified
                && options.infer().isEmpty()

   * otherwise returns an empty stream.
   */
  public static <T> Stream<T> stream(com.google.common.base.Optional<T> optional) {
    return optional.isPresent() ? Stream.of(optional.get()) : Stream.empty();
  }

  /**
   * If a value is present in {@code optional}, returns a stream containing only that element,
   * otherwise returns an empty stream.
   *

        }
    }
    manifest.attributes("Class-Path-Source" to "manifestClasspath")
    manifest.attributes("Class-Path" to classpath)
    if (app.mainClassName.isPresent) {
        manifest.attributes("Main-Class" to app.mainClassName)
    }