* 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

        }
      }
    },
    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) {

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

  @GwtIncompatible // java.io.ObjectOutputStream
  @J2ktIncompatible
  private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
    stream.defaultReadObject();
    expectedValuesPerKey = DEFAULT_VALUES_PER_KEY;

    return Multisets.iteratorImpl(this);
  }

  @GwtIncompatible // java.io.ObjectOutputStream
  private void writeObject(ObjectOutputStream stream) throws IOException {
    stream.defaultWriteObject();
    stream.writeObject(type);
    Serialization.writeMultiset(this, stream);
  }

  /**
   * @serialData the {@code Class<E>} for the enum type, the number of distinct elements, the first

  }

  public void testWriteLines_stream() throws IOException {
    sink.writeLines(ImmutableList.of("foo", "bar", "baz").stream());
    String separator = System.getProperty("line.separator");
    assertEquals("foo" + separator + "bar" + separator + "baz" + separator, sink.getString());
  }

  public void testWriteLines_stream_separator() throws IOException {

@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class CountingOutputStream extends FilterOutputStream {

  private long count;

  /**
   * Wraps another output stream, counting the number of bytes written.
   *
   * @param out the output stream to be wrapped
   */
  public CountingOutputStream(OutputStream out) {
    super(checkNotNull(out));
  }

  /** Returns the number of bytes written. */

import com.google.common.base.Ascii;
import com.google.common.collect.testing.SpliteratorTester;
import java.util.Arrays;
import java.util.List;
import java.util.Spliterator;
import java.util.stream.DoubleStream;
import java.util.stream.IntStream;
import java.util.stream.LongStream;
import junit.framework.TestCase;

/** Tests for {@code CollectSpliterators}. */
@GwtCompatible
@ElementTypesAreNonnullByDefault

  private void writeObject(ObjectOutputStream stream) throws IOException {
    stream.defaultWriteObject();
    stream.writeInt(size());
    for (E e : this) {
      stream.writeObject(e);
    }
  }

  @SuppressWarnings("unchecked")
  @J2ktIncompatible
  private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
    stream.defaultReadObject();

   */
  public abstract Writer openStream() throws IOException;

  /**
   * Opens a new buffered {@link Writer} for writing to this sink. The returned stream is not
   * required to be a {@link BufferedWriter} in order to allow implementations to simply delegate to
   * {@link #openStream()} when the stream returned by that method does not benefit from additional
   * buffering. This method returns a new, independent writer each time it is called.
   *

    String separator = System.getProperty("line.separator");
    sink.writeLines(lines.stream());

    assertContainsExpectedLines(separator);
  }

  public void testWriteLinesStream_specificSeparator() throws IOException {
    String separator = "\r\n";
    sink.writeLines(lines.stream(), separator);

    assertContainsExpectedLines(separator);
  }