}

      override fun fromDer(reader: DerReader): Any? {
        if (isOptional && !reader.hasNext()) return optionalValue

        val peekedHeader =
          reader.peekHeader()
            ?: throw ProtocolException("expected a value at $reader")
        for ((_, adapter) in choices) {
          if (adapter.matches(peekedHeader)) {
            return adapter.fromDer(reader)
          }
        }

	if r == nil {
		return 0
	}
	return atomic.LoadInt64(&r.bytesRead)
}

func newCountUpReader(reader io.Reader) *countUpReader {
	return &countUpReader{
		reader: reader,
	}
}

type progressReader struct {
	rc              io.ReadCloser
	scannedReader   *countUpReader
	processedReader *countUpReader

	closedMu sync.Mutex
	closer   io.ReadCloser
	closed   bool
}

        // of
        // InputStream.read(byte[], int, int)
        // See https://github.com/google/guava/issues/3542
        Reader reader = new StringReader(cannotDecode);
        InputStream decodingStream = encoding.decodingStream(reader);
        try {
          ByteStreams.exhaust(decodingStream);
          fail("Expected DecodingException");
        } catch (DecodingException expected) {

    String result = CharStreams.toString(joinedReader);
    assertEquals(testString.length() * 3, result.length());
  }

  public void testReady() throws Exception {
    CharSource source = newCharSource("a");
    Iterable<? extends CharSource> list = ImmutableList.of(source, source);
    Reader joinedReader = CharSource.concat(list).openStream();

    String result = CharStreams.toString(joinedReader);
    assertEquals(testString.length() * 3, result.length());
  }

  public void testReady() throws Exception {
    CharSource source = newCharSource("a");
    Iterable<? extends CharSource> list = ImmutableList.of(source, source);
    Reader joinedReader = CharSource.concat(list).openStream();

        }
    }

    /**
     * {@link Reader}からテキストを読み込みます。
     * <p>
     * {@link Reader}はクローズされません。
     * </p>
     *
     * @param reader
     *            読み込み文字ストリーム。{@literal null}であってはいけません
     * @return テキスト
     */
    public static String readText(final Reader reader) {
        assertArgumentNotNull("reader", reader);

        final StringBuilder buf = new StringBuilder(BUF_SIZE);

// disconnectReader will ensure that no reads can take place on
// the upstream reader after close has been called.
type disconnectReader struct {
	r  io.Reader
	mu sync.Mutex
}

func (d *disconnectReader) Read(p []byte) (n int, err error) {
	d.mu.Lock()
	defer d.mu.Unlock()
	if d.r != nil {
		return d.r.Read(p)
	}
	return 0, errors.New("reader closed")
}

func (d *disconnectReader) Close() error {

    while (lines.peek() == null) {
      Java8Compatibility.clear(cbuf);
      // The default implementation of Reader#read(CharBuffer) allocates a
      // temporary char[], so we call Reader#read(char[], int, int) instead.
      int read = (reader != null) ? reader.read(buf, 0, buf.length) : readable.read(cbuf);
      if (read == -1) {
        lineBuf.finish();
        break;
      }

        assertArgumentNotNull("reader", reader);

        return () -> new LineIterator(reader);
    }

    /**
     * インスタンスを構築します。
     *
     * @param reader
     *            文字列を読み込む{@link Reader}。{@literal null}であってはいけません
     */
    public LineIterator(final Reader reader) {
        assertArgumentNotNull("reader", reader);
        this.reader = new BufferedReader(reader);
    }

    /**

    }

    @Nonnull
    default T read(@Nonnull Reader reader) throws XmlReaderException {
        return read(reader, true);
    }

    @Nonnull
    default T read(@Nonnull Reader reader, boolean strict) throws XmlReaderException {
        return read(XmlReaderRequest.builder().reader(reader).strict(strict).build());
    }

    @Nonnull