*
   * @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) {

        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

                    .setProcessPlugins(request.isProcessPlugins());
            ProjectBuildingResult res;
            if (request.getPath().isPresent()) {
                Path path = request.getPath().get();
                res = builder.build(path.toFile(), req);
            } else if (request.getSource().isPresent()) {
                Source source = request.getSource().get();
                ModelSource2 modelSource = new SourceWrapper(source);

     * 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()

        public String testDoUpgradeLogic(UpgradeContext context, String expectedTargetModel) {
            UpgradeOptions options = context.options();
            if (options.modelVersion().isPresent()) {
                return options.modelVersion().get();
            } else if (options.all().orElse(false)) {
                return "4.1.0";
            } else {
                return "4.0.0";
            }

        assertNotNull(resolved);
        assertNotNull(resolved.getPath());
        Optional<Path> op = session.getArtifactPath(resolved);
        assertTrue(op.isPresent(), "Expected " + op + ".isPresent() to return true");
        assertEquals(resolved.getPath(), op.get());
    }

    @Test
    void testBuildProject() {

    }

    @Override
    public boolean presentInConfig(
            org.apache.maven.model.Profile profile, ProfileActivationContext context, ModelProblemCollector problems) {
        return getActivationPackaging(profile).isPresent();
    }

    private static boolean isPackaging(ProfileActivationContext context, String p) {
        String packaging = context.getUserProperties().get(ProfileActivationContext.PROPERTY_NAME_PACKAGING);

@GwtCompatible
final class Present<T> extends Optional<T> {
  private final T reference;

  Present(T reference) {
    this.reference = reference;
  }

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

  @Override
  public T get() {
    return reference;
  }

  @Override
  public T or(T defaultValue) {