*
   * @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) {

    /**
     * Kotlin file-facade classes can't have kdoc comments.
     */
    private boolean isKotlinFileFacadeClass(JApiCompatibility member) {
        return member instanceof JApiClass && ((JApiClass) member).getNewClass().isPresent() && KotlinMetadataQueries.INSTANCE.isKotlinFileFacadeClass(((JApiClass) member).getNewClass().get());
    }

        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

            })
        }
        .reduce { acc, next ->
            acc.zip(next) { left, right ->
                when {
                    !left.isPresent -> right
                    !right.isPresent -> left
                    else -> Optional.of(combiner(left.get(), right.get()))
                }
            }
        }
        .map { it.orElse(null) }

   * 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.
   *

        final int maxQueryLength = fessConfig.getQueryMaxLengthAsInteger();

        stream(conditions.get(SearchRequestParams.AS_OCCURRENCE))
                .of(stream -> stream.filter(this::isOccurrence).findFirst().ifPresent(q -> queryBuf.insert(0, q + ":")));

        stream(conditions.get(SearchRequestParams.AS_Q))
                .of(stream -> stream.filter(q -> StringUtil.isNotBlank(q) && q.length() <= maxQueryLength)

        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";
            }

        })
    }

    val integTestUseAgentSysPropName = "org.gradle.integtest.agent.allowed"
    val integtestAgentAllowed = project.providers.gradleProperty(integTestUseAgentSysPropName);
    if (integtestAgentAllowed.isPresent) {
        val shouldUseAgent = integtestAgentAllowed.get().toBoolean()
        systemProperties[integTestUseAgentSysPropName] = shouldUseAgent.toString()
    }
}


private