go func() {
			// Initialize MRF meta header.
			var data [4]byte
			binary.LittleEndian.PutUint16(data[0:2], healMRFMetaFormat)
			binary.LittleEndian.PutUint16(data[2:4], healMRFMetaVersionV1)
			mw := msgp.NewWriter(w)
			n, err := mw.Write(data[:])
			if err != nil {
				w.CloseWithError(err)
				return
			}
			if n != len(data) {
				w.CloseWithError(io.ErrShortWrite)
				return
			}

	if err != nil {
		return err
	}
	defer r.Close()

	gw, err := os.Create(oldLgFile + ".gz")
	if err != nil {
		return err
	}
	defer gw.Close()

	var wc io.WriteCloser = gzip.NewWriter(gw)
	if _, err = io.Copy(wc, r); err != nil {
		return err
	}

	if err = wc.Close(); err != nil {
		return err
	}

	// Persist to disk any caches.
	if err = gw.Sync(); err != nil {

      assertThrows(IOException.class, () -> okSource.copyTo(new TestCharSink(option)));
      // ensure reader was closed IF it was opened (depends on implementation whether or not it's
      // opened at all if sink.newWriter() throws).
      assertTrue(
          "stream not closed when copying to sink with option: " + option,
          !okSource.wasStreamOpened() || okSource.wasStreamClosed());
    }
  }

      assertThrows(IOException.class, () -> okSource.copyTo(new TestCharSink(option)));
      // ensure reader was closed IF it was opened (depends on implementation whether or not it's
      // opened at all if sink.newWriter() throws).
      assertTrue(
          "stream not closed when copying to sink with option: " + option,
          !okSource.wasStreamOpened() || okSource.wasStreamClosed());
    }
  }

	// err is a persistent error.
	// It is only the responsibility of every exported method of Writer to
	// ensure that this error is sticky.
	err error
}

// NewWriter creates a new Writer writing to w.
func NewWriter(w io.Writer) *Writer {
	return &Writer{w: w, curr: &regFileWriter{w, 0}}
}

type fileWriter interface {
	io.Writer
	fileState

	ReadFrom(io.Reader) (int64, error)
}

//		if err := os.WriteFile("/tmp/biggest.zip", biggestZip, 0666); err != nil {
//			log.Fatal(err)
//		}
//	}
//
//	func makeZip(name string, r io.Reader) []byte {
//		var buf bytes.Buffer
//		w := zip.NewWriter(&buf)
//		wf, err := w.Create(name)
//		if err != nil {
//			log.Fatal(err)
//		}
//		if _, err = io.Copy(wf, r); err != nil {
//			log.Fatal(err)
//		}
//		if err := w.Close(); err != nil {

		"policy":    encodedPolicy,
		"signature": signature,
	}

	maps.Copy(formData, formInputData)

	// Create the multipart form.
	var buf bytes.Buffer
	w := multipart.NewWriter(&buf)

	// Set the normal formData
	for k, v := range formData {
		w.WriteField(k, v)
	}
	// Set the File formData
	writer, err := w.CreateFormFile("file", "upload.txt")
	if err != nil {

	_, err := dst.Write([]byte{dataUsageCacheVerCurrent})
	if err != nil {
		return err
	}
	enc, err := zstd.NewWriter(dst,
		zstd.WithEncoderLevel(zstd.SpeedFastest),
		zstd.WithWindowSize(1<<20),
		zstd.WithEncoderConcurrency(2))
	if err != nil {
		return err
	}
	mEnc := msgp.NewWriter(enc)
	err = d.EncodeMsg(mEnc)
	if err != nil {
		return err
	}
	err = mEnc.Flush()
	if err != nil {

	b := bytebufferpool.Get()
	bc := bytebufferpool.Get()
	defer func() {
		b.Reset()
		bc.Reset()

		bytebufferpool.Put(b)
		bytebufferpool.Put(bc)
	}()

	w, err := zstd.NewWriter(bc)
	if err != nil {
		return nil, nil, err
	}

	if _, err = io.Copy(w, io.TeeReader(reader, b)); err != nil {
		return nil, nil, err
	}

	w.Close()
	return bc.Bytes(), b.Bytes(), nil
}

	// Write a version for making *incompatible* changes.
	// The AdminClient will reject any version it does not know.
	var inspectZipW *zip.Writer
	if publicKey != nil {
		w.WriteHeader(200)
		stream := estream.NewWriter(w)
		defer stream.Close()

		clusterKey, err := bytesToPublicKey(getSubnetAdminPublicKey())
		if err != nil {
			bugLogIf(ctx, stream.AddError(err.Error()))
			return
		}