checkNotNull(from);
    checkNotNull(to);
    char[] buf = new char[DEFAULT_BUF_SIZE];
    int nRead;
    long total = 0;
    while ((nRead = from.read(buf)) != -1) {
      to.append(buf, 0, nRead);
      total += nRead;
    }
    return total;
  }

  /**
   * Copies all characters between the {@link Reader} and {@link Writer} objects. Does not close or

          try (InputStreamReader reader = new InputStreamReader(byteSource.openStream(), cs)) {
            int nRead = 0;
            while (remaining > 0 && (nRead = reader.read(buffer, bufIndex, remaining)) != -1) {
              bufIndex += nRead;
              remaining -= nRead;
            }
            if (nRead == -1) {
              // we reached EOF
              return new String(buffer, 0, bufIndex);
            }

}

func (r *checksumReader) Read(b []byte) (n int, err error) {
	if r.err != nil {
		return 0, r.err
	}
	n, err = r.rc.Read(b)
	r.hash.Write(b[:n])
	r.nread += uint64(n)
	if r.nread > r.f.UncompressedSize64 {
		return 0, ErrFormat
	}
	if err == nil {
		return
	}
	if err == io.EOF {
		if r.nread != r.f.UncompressedSize64 {
			return 0, io.ErrUnexpectedEOF
		}

	buf := make([]byte, 1)
	if _, err := b.Read(nil); err != nil {
		t.Fatalf("1st nil Read = %v; want nil", err)
	}
	if _, err := b.Read(buf); err != errFake {
		t.Fatalf("1st Read = %v; want errFake", err)
	}
	if _, err := b.Read(nil); err != nil {
		t.Fatalf("2nd nil Read = %v; want nil", err)
	}
	if _, err := b.Read(buf); err != nil {
		t.Fatalf("3rd Read with buffer = %v; want nil", err)
	}

		t.Errorf("Read error: got %T, want testError1", err)
	}
	if _, err := rb.TryRead([]byte{0}); err != (testError1{}) {
		t.Errorf("Read error: got %T, want testError1", err)
	}
	rb.CloseWithError(testError2{})
	if _, err := rb.Read(nil); err != (testError1{}) {
		t.Errorf("Read error: got %T, want testError1", err)
	}
	if _, err := rb.Read([]byte{0}); err != (testError1{}) {

}

var errUnreadByte = errors.New("bytes.Buffer: UnreadByte: previous operation was not a successful read")

// UnreadByte unreads the last byte returned by the most recent successful
// read operation that read at least one byte. If a write has happened since
// the last read, if the last read returned an error, or if the read read zero
// bytes, UnreadByte returns an error.
func (b *Buffer) UnreadByte() error {

      }
    }

    override fun read(
      sink: Buffer,
      byteCount: Long,
    ): Long {
      require(byteCount >= 0L) { "byteCount < 0: $byteCount" }
      check(!closed) { "closed" }
      if (bytesRemaining == 0L) return -1

      val read = super.read(sink, minOf(bytesRemaining, byteCount))
      if (read == -1L) {

	return sr
}

// remaining returns the number of unread bytes
// if EOF for the underlying reader has not yet been found,
// maximum possible integer value will be returned
func (s *scanner) remaining() int64 {
	if atomic.LoadInt64(&s.end) == maxInt {
		return maxInt
	}
	return atomic.LoadInt64(&s.end) - s.pos
}

// read byte at current position (without advancing)

	debug  bool
}

func (cr *s3UnsignedChunkedReader) Close() (err error) {
	return cr.err
}

// Read - implements `io.Reader`, which transparently decodes
// the incoming AWS Signature V4 streaming signature.
func (cr *s3UnsignedChunkedReader) Read(buf []byte) (n int, err error) {
	// First, if there is any unread data, copy it to the client
	// provided buffer.
	if cr.offset > 0 {
		n = copy(buf, cr.buffer[cr.offset:])

			return n - remain, b.readErr()
		}
	}
}

// Read reads data into p.
// It returns the number of bytes read into p.
// The bytes are taken from at most one Read on the underlying [Reader],
// hence n may be less than len(p).
// To read exactly len(p) bytes, use io.ReadFull(b, p).
// If the underlying [Reader] can return a non-zero count with io.EOF,
// then this Read method can do so as well; see the [io.Reader] docs.