@Named
@Singleton
public class DefaultMetadataReader implements MetadataReader {

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

        return read(Files.newInputStream(input.toPath()), options);
    }

    public Metadata read(Reader input, Map<String, ?> options) throws IOException {

    /**
     * Attaches [tag] to the request using [T] as a key. Tags can be read from a request using
     * [Request.tag]. Use null to remove any existing tag assigned for [T].
     *
     * Use this API to attach timing, debugging, or other application data to a request so that
     * you may read it in interceptors, event listeners, or callbacks.
     */
    @JvmName("reifiedTag")

 *
 * Every [edit] call must be matched by a call to [Editor.commit] or [Editor.abort]. Committing is
 * atomic: a read observes the full set of values as they were before or after the commit, but never
 * a mix of values.
 *
 * Clients call [get] to read a snapshot of an entry. The read will observe the value at the time
 * that [get] was called. Updates and removals after the call do not impact ongoing reads.
 *

    assertTrue(source.wasStreamOpened());
    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());
  }

//   - Exactly 0 bytes are read and EOF is hit.
//   - Exactly 1 block of zeros is read and EOF is hit.
//   - At least 2 blocks of zeros are read.
func (tr *Reader) readHeader() (*Header, *block, error) {
	// Two blocks of zero bytes marks the end of the archive.
	if _, err := io.ReadFull(tr.r, tr.blk[:]); err != nil {
		return nil, nil, err // EOF is okay here; exactly 0 bytes read
	}

            if (inputStream != null) {
                return xml.read(inputStream, request.isStrict());
            } else if (reader != null) {
                return xml.read(reader, request.isStrict());
            } else if (path != null) {
                try (InputStream is = Files.newInputStream(path)) {
                    return xml.read(is, request.isStrict());
                }
            } else {

 *       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

      @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
      }
    }
  }

  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

		}
	}
	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 {