@Throws(IOException::class)
      override fun read(
        sink: Buffer,
        byteCount: Long,
      ): Long {
        val buffer = Buffer()
        val read = delegate.read(buffer, byteCount)
        if (read != -1L) {
          sink.write(buffer.readByteString().toAsciiUppercase())
        }
        return read
      }
    }
  }

 *       block indefinitely or fail if the source creates an infinite reader.
 *   <li><b>Non-destructive:</b> A <i>destructive</i> reader will consume or otherwise alter the
 *       source as they are read from it. A source that provides such readers will not be reusable,
 *       and operations that read from the stream (including {@link #length()}, in some

		}
	}
	return &Reader{
		src:      r,
		md5:      md5.New(),
		checksum: etag,
	}
}

// Read reads up to len(p) bytes from the underlying
// io.Reader as specified by the io.Reader interface.
func (r *Reader) Read(p []byte) (int, error) {
	n, err := r.src.Read(p)
	r.readN += int64(n)
	r.md5.Write(p[:n])

	if err == io.EOF && len(r.checksum) != 0 {

  private val countingSource: CountingSource = CountingSource(source)
  private val source: BufferedSource = countingSource.buffer()

  /** Total bytes read thus far. */
  private val byteCount: Long
    get() = countingSource.bytesRead - source.buffer.size

  /** How many bytes to read before [peekHeader] should return false, or -1L for no limit. */
  private var limit = -1L

* `write(data)`: Writes `data` (`str` or `bytes`) to the file.
* `read(size)`: Reads `size` (`int`) bytes/characters of the file.
* `seek(offset)`: Goes to the byte position `offset` (`int`) in the file.
    * E.g., `await myfile.seek(0)` would go to the start of the file.
    * This is especially useful if you run `await myfile.read()` once and then need to read the contents again.
* `close()`: Closes the file.

        reader.setScrollSize(1000);
        int count = 0;
        Set<String> valueSet = Collections.synchronizedSet(new HashSet<>());
        Map<String, Object> source;
        while ((source = reader.read()) != null) {
            assertTrue(source.get("field1").toString().startsWith("test"));
            valueSet.add(source.get("field1").toString());
            count++;
        }
        assertEquals(num, count);

    // The stream reports no bytes... importantly, it doesn't read the byte at index 5 when it
    // should be reading the byte at index 10.
    // We could use a custom InputStream instead to make the read start at index 10, but since this
    // is a racy situation anyway, this behavior seems reasonable.
    assertEquals(-1, in.read());
  }

  private static class AppendableByteSource extends ByteSource {

		panic("Failed to acquire read lock")
	}
	// fmt.Println("1st read lock acquired, waiting...")

	if !lrwm.GetRLock(ctx, "", "object1", time.Second) {
		panic("Failed to acquire read lock")
	}
	// fmt.Println("2nd read lock acquired, waiting...")

	go func() {
		time.Sleep(2 * time.Second)
		lrwm.RUnlock()
		// fmt.Println("1st read lock released, waiting...")
	}()

	go func() {

    @Override
    public Settings read(File input, Map<String, ?> options) throws IOException {
        Objects.requireNonNull(input, "input cannot be null");

        try (InputStream in = Files.newInputStream(input.toPath())) {
            InputSource source = new InputSource(input.toString());
            return new Settings(new SettingsStaxReader().read(in, isStrict(options), source));

        int ftag = in.read();
        int tag = readTagNumber(in, ftag);
        if ( tag != expectTag ) {
            throw new IOException("Unexpected tag " + tag);
        }
        int length = readLength(in, limit, false);
        byte[] content = new byte[length];
        in.read(content);
        return content;
    }