Objects.requireNonNull(output, "output cannot be null");
        Objects.requireNonNull(model, "model cannot be null");

        try (Writer out = output) {
            new MavenXpp3Writer().write(out, model);
        }
    }

    @Override
    public void write(OutputStream output, Map<String, Object> options, Model model) throws IOException {

				// concurrently, check for it before we
				// write the filler byte.
				select {
				case err := <-doneCh:
					if err != nil {
						write([]byte{1})
						write([]byte(err.Error()))
					} else {
						write([]byte{0})
					}
					return
				default:
				}

				// Response not ready, write a filler byte.
				write([]byte{32})
				if canWrite {
					xhttp.Flush(w)
				}

    var b1 = length
    if (isClient) {
      b1 = b1 or B1_FLAG_MASK
      sinkBuffer.writeByte(b1)

      random.nextBytes(maskKey!!)
      sinkBuffer.write(maskKey)

      if (length > 0) {
        val payloadStart = sinkBuffer.size
        sinkBuffer.write(payload)

        sinkBuffer.readAndWriteUnsafe(maskCursor!!)
        maskCursor.seek(payloadStart)
        toggleMask(maskCursor, maskKey)

        // First write
        SuggestWriterResult result1 =
                writer.write(runner.client(), suggester.settings(), suggester.getIndex(), new SuggestItem[] { item }, false);
        assertNotNull(result1);
        assertFalse(result1.hasFailure());

        runner.refresh();

        // Second write with update

      val body = part.body

      sink!!.write(DASHDASH)
      sink.write(boundaryByteString)
      sink.write(CRLF)

      if (headers != null) {
        for (h in 0 until headers.size) {
          sink
            .writeUtf8(headers.name(h))
            .write(COLONSPACE)
            .writeUtf8(headers.value(h))
            .write(CRLF)
        }
      }

    assertEquals(written, counter.getCount());

    counter.write(0);
    written += 1;
    assertEquals(written, out.size());
    assertEquals(written, counter.getCount());

    byte[] data = new byte[10];
    counter.write(data);
    written += 10;
    assertEquals(written, out.size());
    assertEquals(written, counter.getCount());

    counter.write(data, 0, 5);
    written += 5;
    assertEquals(written, out.size());

    DeflaterSink(buffer, Deflater(Deflater.DEFAULT_COMPRESSION, true)).use { sink ->
      sink.write(Buffer().write(message1), message1.size.toLong())
    }
    buffer.writeByte(0x00)
    // Trailing data. We use the Okio segment size to make sure it's still in the input buffer.
    buffer.write(ByteArray(8192))
    inflater.inflate(buffer)
    assertThat(buffer.readByteString()).isEqualTo(message1)

	prelude := buf.Bytes()
	binary.Write(buf, binary.BigEndian, crc32.ChecksumIEEE(prelude))
	buf.Write(header)
	message := buf.Bytes()
	binary.Write(buf, binary.BigEndian, crc32.ChecksumIEEE(message))

	fmt.Println(buf.Bytes())
}

func genProgressHeader() {
	buf := new(bytes.Buffer)

	buf.WriteByte(13)
	buf.WriteString(":message-type")
	buf.WriteByte(7)

			writeRng.Read(buf)
			// Write
			n, err := rb.Write(buf[:writeRng.Intn(len(buf))])
			if err != nil {
				t.Fatalf("write failed: %v", err)
			}
			wroteBytes += n
			wrote.Write(buf[:n])
			debugln("WRITE 1\t", n, wroteBytes)

			// WriteString
			n, err = rb.WriteString(string(buf[:writeRng.Intn(len(buf))]))
			if err != nil {
				t.Fatalf("write failed: %v", err)
			}
			wroteBytes += n

		return
	}
	// write "Path"
	err = en.Append(0xa4, 0x50, 0x61, 0x74, 0x68)
	if err != nil {
		return
	}
	err = en.WriteString(z.Path)
	if err != nil {
		err = msgp.WrapError(err, "Path")
		return
	}
	// write "Creds"
	err = en.Append(0xa5, 0x43, 0x72, 0x65, 0x64, 0x73)
	if err != nil {
		return
	}
	// map header, size 3
	// write "AccessKey"