cmdAndArguments.add("--install-toolchains");
            cmdAndArguments.add(mavenOptions.altInstallationToolchains().get());
        }
        if (mavenOptions.logFile().isPresent()) {
            cmdAndArguments.add("--log-file");
            cmdAndArguments.add(mavenOptions.logFile().get());
        }
        if (mavenOptions.color().isPresent()) {
            cmdAndArguments.add("--color");

    }

    protected <T> Optional<T> returnFirstPresentOrEmpty(Function<O, Optional<T>> getter) {
        for (O option : options) {
            Optional<T> o = getter.apply(option);
            if (o.isPresent()) {
                return o;
            }
        }
        return Optional.empty();
    }

    protected Optional<List<String>> collectListIfPresentOrEmpty(Function<O, Optional<List<String>>> getter) {

        MavenOptions mavenOptions = context.invokerRequest.options();
        if (mavenOptions.failFast().isPresent()) {
            return MavenExecutionRequest.REACTOR_FAIL_FAST;
        } else if (mavenOptions.failAtEnd().isPresent()) {
            return MavenExecutionRequest.REACTOR_FAIL_AT_END;
        } else if (mavenOptions.failNever().isPresent()) {
            return MavenExecutionRequest.REACTOR_FAIL_NEVER;
        } else {

        if (invokerRequest.options().help().isPresent()) {
            Consumer<String> writer = determineWriter(context);
            invokerRequest.options().displayHelp(context.invokerRequest.parserRequest(), writer);
            throw new ExitException(0);
        }
        if (invokerRequest.options().showVersionAndExit().isPresent()) {
            showVersion(context);
            throw new ExitException(0);

  Optional() {}

  /**
   * Returns {@code true} if this holder contains a (non-null) instance.
   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> no differences.
   */
  public abstract boolean isPresent();

  /**
   * Returns the contained instance, which must be present. If the instance might be absent, use
   * {@link #or(Object)} or {@link #orNull} instead.
   *

        for (String selector : projectSelectors) {
            Optional<MavenProject> optSelectedProject =
                    findOptionalProjectBySelector(projects, baseDirectory, selector);
            if (!optSelectedProject.isPresent()) {
                String message = "Could not find the selected project in the reactor: " + selector;
                throw new MavenExecutionException(message, request.getPom());
            }

  }

  public void testIsPresent_no() {
    assertFalse(Optional.absent().isPresent());
  }

  @SuppressWarnings("OptionalOfRedundantMethod") // Unit tests for Optional
  public void testIsPresent_yes() {
    assertTrue(Optional.of("training").isPresent());
  }

  public void testGet_absent() {
    Optional<String> optional = Optional.absent();

            String fieldKey = field.getKey();
            String fieldDescription = "Configure " + fieldKey + ": " + field.getDescription();
            if (field.getOptions().isPresent()) {
                // list options
                ListPromptBuilder listPromptBuilder =
                        promptBuilder.createListPrompt().name(fieldKey).message(fieldDescription);

   *
   * @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