"github.com/tinylib/msgp/msgp"
	"github.com/valyala/bytebufferpool"
)

// metadata stream format:
//
// The stream is s2 compressed.
// https://github.com/klauspost/compress/tree/master/s2#s2-compression
// This ensures integrity and reduces the size typically by at least 50%.
//
// All stream elements are msgpack encoded.
//
// 1 Integer, metacacheStreamVersion of the writer.

    }
  }

  /**
   * Returns a {@link Stream} containing the elements of the first stream, followed by the elements
   * of the second stream, and so on.
   *
   * <p>This is equivalent to {@code Stream.of(streams).flatMap(stream -> stream)}, but the returned
   * stream may perform better.
   *
   * @see Stream#concat(Stream, Stream)
   */

    }
  }

  /**
   * Returns a {@link Stream} containing the elements of the first stream, followed by the elements
   * of the second stream, and so on.
   *
   * <p>This is equivalent to {@code Stream.of(streams).flatMap(stream -> stream)}, but the returned
   * stream may perform better.
   *
   * @see Stream#concat(Stream, Stream)
   */

   * iterator supports it.
   *
   * <p><b>{@code Stream} equivalent:</b> to concatenate an arbitrary number of streams, use {@code
   * Stream.of(stream1, stream2, ...).flatMap(s -> s)}. If the sources are iterables, use {@code
   * Stream.of(iter1, iter2, ...).flatMap(Streams::stream)}.
   *
   * @throws NullPointerException if any of the provided iterables is {@code null}
   * @since 20.0

  }

  /**
   * Opens a new {@link Stream} for reading text one line at a time from this source. This method
   * returns a new, independent stream each time it is called.
   *
   * <p>The returned stream is lazy and only reads from the source in the terminal operation. If an
   * I/O error occurs while the stream is reading from the source or when the stream is closed, an
   * {@link UncheckedIOException} is thrown.
   *

   *
   * <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) {

  }

  /**
   * Opens a new {@link Stream} for reading text one line at a time from this source. This method
   * returns a new, independent stream each time it is called.
   *
   * <p>The returned stream is lazy and only reads from the source in the terminal operation. If an
   * I/O error occurs while the stream is reading from the source or when the stream is closed, an
   * {@link UncheckedIOException} is thrown.
   *

    }

    /**
     * Method write.
     *
     * @param stream a stream object.
     * @param persistedToolchains a persistedToolchains object.
     * @throws IOException java.io.IOException if any.
     */
    public void write(OutputStream stream, PersistedToolchains persistedToolchains) throws IOException {
        try {
            delegate.write(stream, persistedToolchains.getDelegate());
        } catch (XMLStreamException e) {

   */
  @GwtIncompatible
  @J2ktIncompatible
    private void writeObject(ObjectOutputStream stream) throws IOException {
    stream.defaultWriteObject();
    stream.writeObject(keyComparator());
    stream.writeObject(valueComparator());
    Serialization.writeMultimap(this, stream);
  }

  @GwtIncompatible
  @J2ktIncompatible
    @SuppressWarnings("unchecked") // reading data stored by writeObject

  public void testToOptionalEmpty() {
    assertThat(Stream.empty().collect(toOptional())).isEmpty();
  }

  public void testToOptionalSingleton() {
    assertThat(Stream.of(1).collect(toOptional())).hasValue(1);
  }

  public void testToOptionalNull() {
    Stream<@Nullable Object> stream = Stream.of((Object) null);
    assertThrows(NullPointerException.class, () -> stream.collect(toOptional()));
  }