}
      }
    },
    STREAMS_FIND_LAST {
      @Override
      Object operate(Stream<?> stream) {
        return Streams.findLast(stream);
      }
    },
    REDUCE_LAST {
      @Override
      Object operate(Stream<?> stream) {
        return stream.reduce((a, b) -> b);
      }
    },
    REDUCE_LAST_PARALLEL {
      @Override
      Object operate(Stream<?> stream) {

      check(!isLocallyInitiated) { "locally-initiated streams shouldn't have headers yet" }
      headersQueue += headers
    } else {
      check(isLocallyInitiated) { "remotely-initiated streams should have headers" }
    }
  }

  /**
   * Returns true if this stream is open. A stream is open until either:
   *
   *  * A `SYN_RESET` frame abnormally terminates the stream.

   *
   * <p><b>Java 8+ users:</b> If passing a single element {@code e}, the {@code Stream} equivalent
   * of this method is {@code Stream.generate(() -> e)}. Otherwise, put the elements in a collection
   * and use {@code Stream.generate(() -> collection).flatMap(Collection::stream)}.
   */
  @SafeVarargs
  public static <T extends @Nullable Object> Iterable<T> cycle(T... elements) {

package com.google.common.io;

/**
 * Interface for a supplier of streams that can report whether a stream was opened and whether that
 * stream was closed. Intended for use in a test where only a single stream should be opened and
 * possibly closed.
 *
 * @author Colin Decker
 */
public interface TestStreamSupplier {

  /** Returns whether or not a new stream was opened. */
  boolean wasStreamOpened();

  /**
   * A collector that converts a stream of zero or one elements to an {@code Optional}.
   *
   * @throws IllegalArgumentException if the stream consists of two or more elements.
   * @throws NullPointerException if any element in the stream is {@code null}.
   * @return {@code Optional.of(onlyElement)} if the stream has exactly one element (must not be

  }

  /**
   * Concatenates multiple {@link ByteSource} instances into a single source. Streams returned from
   * the source will contain the concatenated data from the streams of the underlying sources.
   *
   * <p>Only one underlying stream will be open at a time. Closing the concatenated stream will
   * close the open underlying stream.
   *
   * @param sources the sources to concatenate

      Map<K, V> map, ObjectOutputStream stream) throws IOException {
    stream.writeInt(map.size());
    for (Map.Entry<K, V> entry : map.entrySet()) {
      stream.writeObject(entry.getKey());
      stream.writeObject(entry.getValue());
    }
  }

  /**
   * Populates a map by reading an input stream, as part of deserialization. See {@link #writeMap}
   * for the data format.
   */

  /**
   * Copies all bytes from the input stream to the output stream. Does not close or flush either
   * stream.
   *
   * <p><b>Java 9 users and later:</b> this method should be treated as deprecated; use the
   * equivalent {@link InputStream#transferTo} method instead.
   *
   * @param from the input stream to read from
   * @param to the output stream to write to
   * @return the number of bytes copied

    @Execute
    @Secured({ ROLE, ROLE + VIEW })
    public ActionResponse download(final String id) {
        if (stream(fessConfig.getIndexBackupAllTargets()).get(stream -> stream.anyMatch(s -> s.equals(id)))) {
            if ("system.properties".equals(id)) {
                return asStream(id).contentTypeOctetStream().stream(out -> {
                    try (final ByteArrayOutputStream baos = new ByteArrayOutputStream()) {

  private void writeObject(ObjectOutputStream stream) throws IOException {
    stream.defaultWriteObject();
    Serialization.writeMultimap(this, stream);
  }

  @GwtIncompatible // java.io.ObjectInputStream
  @J2ktIncompatible
  private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
    stream.defaultReadObject();
    int keyCount = stream.readInt();
    if (keyCount < 0) {