*
   * @throws IOException if an I/O error occurs while opening the writer
   * @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);
  }

  /**

  private TestCharSink sink;

  @Override
  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());

  @Override
  protected void setUp() throws Exception {
    sink = new TestByteSink();
  }

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

    out.write(new byte[] {1, 2, 3, 4});
    out.close();

    assertTrue(sink.wasStreamClosed());

  @Override
  protected void setUp() throws Exception {
    sink = new TestByteSink();
  }

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

    out.write(new byte[] {1, 2, 3, 4});
    out.close();

    assertTrue(sink.wasStreamClosed());

    } finally {
      out.close();
    }

    assertContainsExpectedBytes();
  }

  public void testOpenBufferedStream() throws IOException {
    OutputStream out = sink.openBufferedStream();
    try {
      ByteStreams.copy(new ByteArrayInputStream(data), out);
    } finally {
      out.close();
    }

    assertContainsExpectedBytes();
  }

    } finally {
      out.close();
    }

    assertContainsExpectedBytes();
  }

  public void testOpenBufferedStream() throws IOException {
    OutputStream out = sink.openBufferedStream();
    try {
      ByteStreams.copy(new ByteArrayInputStream(data), out);
    } finally {
      out.close();
    }

    assertContainsExpectedBytes();
  }

   *
   * @throws IOException if an I/O error occurs while opening the stream
   * @since 15.0 (in 14.0 with return type {@link BufferedOutputStream})
   */
  public OutputStream openBufferedStream() throws IOException {
    OutputStream out = openStream();
    return (out instanceof BufferedOutputStream)
        ? (BufferedOutputStream) out
        : new BufferedOutputStream(out);
  }

  /**

    }
    reader.close();
    writer.close();

    assertExpectedString(writer.toString());
  }

  public void testOpenBufferedStream() throws IOException {
    BufferedReader reader = source.openBufferedStream();

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

      assertExpectedBytes(readBytes);
    } finally {
      in.close();
    }
  }

  public void testOpenBufferedStream() throws IOException {
    InputStream in = source.openBufferedStream();
    try {
      byte[] readBytes = ByteStreams.toByteArray(in);
      assertExpectedBytes(readBytes);
    } finally {
      in.close();
    }
  }

    }
    reader.close();
    writer.close();

    assertExpectedString(writer.toString());
  }

  public void testOpenBufferedStream() throws IOException {
    BufferedReader reader = source.openBufferedStream();

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