*
   * @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);
  }

  /**

   *
   * <p>The caller is responsible for ensuring that the returned reader is closed.
   *
   * @throws IOException if an I/O error occurs while of opening the reader
   */
  public BufferedReader openBufferedStream() throws IOException {
    Reader reader = openStream();
    return (reader instanceof BufferedReader)
        ? (BufferedReader) reader
        : new BufferedReader(reader);
  }

  /**

  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());

   *
   * @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);
  }

  /**

  @Override
  public void setUp() {
    source = new TestCharSource(STRING);
  }

  public void testOpenBufferedStream() throws IOException {
    BufferedReader reader = source.openBufferedStream();
    assertTrue(source.wasStreamOpened());
    assertFalse(source.wasStreamClosed());

    StringWriter writer = new StringWriter();
    char[] buf = new char[64];
    int read;