assertFalse(source.wasStreamClosed());

    StringWriter writer = new StringWriter();
    char[] buf = new char[64];
    int read;
    while ((read = reader.read(buf)) != -1) {
      writer.write(buf, 0, read);
    }
    reader.close();
    writer.close();

    assertTrue(source.wasStreamClosed());
    assertEquals(STRING, writer.toString());
  }

  public void testCopyTo_appendable() throws IOException {

    StringBuilder builder = new StringBuilder();
    Writer writer = new AppendableWriter(builder);

    writer.write("Hello".toCharArray());
    writer.write(',');
    writer.write(0xBEEF0020); // only lower 16 bits are important
    writer.write("Wo");
    writer.write("Whirled".toCharArray(), 3, 2);
    writer.write("Mad! Mad, I say", 2, 2);

    assertEquals("Hello, World!", builder.toString());
  }

   * @since 15.0 (in 14.0 with return type {@link BufferedWriter})
   */
  public Writer openBufferedStream() throws IOException {
    Writer writer = openStream();
    return (writer instanceof BufferedWriter)
        ? (BufferedWriter) writer
        : new BufferedWriter(writer);
  }

  /**
   * Writes the given character sequence to this sink.
   *

    Writer writer = sink.openStream();
    try {
      writer.write(data);
    } finally {
      writer.close();
    }

    assertContainsExpectedString();
  }

  public void testOpenBufferedStream() throws IOException {
    Writer writer = sink.openBufferedStream();
    try {
      writer.write(data);
    } finally {
      writer.close();
    }

  public void setUp() {
    sink = new TestCharSink();
  }

  public void testOpenBufferedStream() throws IOException {
    Writer writer = sink.openBufferedStream();
    assertTrue(sink.wasStreamOpened());
    assertFalse(sink.wasStreamClosed());

    writer.write(STRING);
    writer.close();

    assertTrue(sink.wasStreamClosed());
    assertEquals(STRING, sink.getString());
  }

    public CharSource createSource(String string) throws IOException {
      checkNotNull(string);
      File file = createFile();
      Writer writer = new OutputStreamWriter(new FileOutputStream(file), Charsets.UTF_8);
      try {
        writer.write(string);
      } finally {
        writer.close();
      }
      return Files.asCharSource(file, Charsets.UTF_8);
    }

    @Override

      return delegate().last();
    }

    private static final long serialVersionUID = 0;
  }

  public static TestSuite suite() {
    TestSuite suite = new TestSuite();
    suite.addTestSuite(SynchronizedNavigableSetTest.class);
    suite.addTest(
        NavigableSetTestSuiteBuilder.using(
                new TestStringSortedSetGenerator() {

                  @Override

    Thread waiter =
        new Thread() {
          @Override
          public void run() {
            try {
              service.awaitTermination(1, TimeUnit.DAYS);
            } catch (InterruptedException e) {
              return;
            }
          }
        };
    waiter.start();
    awaitTimedWaiting(waiter);
    service.shutdown();

      return delegate().last();
    }

    private static final long serialVersionUID = 0;
  }

  public static TestSuite suite() {
    TestSuite suite = new TestSuite();
    suite.addTestSuite(SynchronizedNavigableSetTest.class);
    suite.addTest(
        NavigableSetTestSuiteBuilder.using(
                new TestStringSortedSetGenerator() {

                  @Override

  }

  /**
   * Adds {@code delta} to the value currently associated with {@code key}, and returns the new
   * value.
   */
  @CanIgnoreReturnValue
  public long addAndGet(K key, long delta) {
    outer:
    while (true) {
      AtomicLong atomic = map.get(key);
      if (atomic == null) {
        atomic = map.putIfAbsent(key, new AtomicLong(delta));
        if (atomic == null) {
          return delta;