private RequestBody gzip(final RequestBody body) {
    return new RequestBody() {
      @Override public MediaType contentType() {
        return body.contentType();
      }

      @Override public long contentLength() {
        return -1; // We don't know the compressed length in advance!
      }

      @Override public void writeTo(BufferedSink sink) throws IOException {

	// http://docs.aws.amazon.com/AmazonS3/latest/API/multiobjectdeleteapi.html
	if r.ContentLength <= 0 {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrMissingContentLength), r.URL)
		return
	}

	// The max. XML contains 100000 object names (each at most 1024 bytes long) + XML overhead
	const maxBodySize = 2 * 100000 * 1024

	if r.ContentLength > maxBodySize {

    val call = client.newCall(Request(server.url("/foo")))
    val response = call.execute()

    // Body contains nothing.
    assertThat(response.body.bytes().size).isEqualTo(0)
    assertThat(response.body.contentLength()).isEqualTo(0)

    // Content-Length header doesn't exist in a 204 response.
    assertThat(response.header("content-length")).isNull()
    assertThat(response.code).isEqualTo(204)

	Date               = "Date"
	ETag               = "ETag"
	ContentType        = "Content-Type"
	ContentMD5         = "Content-Md5"
	ContentEncoding    = "Content-Encoding"
	Expires            = "Expires"
	ContentLength      = "Content-Length"
	ContentLanguage    = "Content-Language"
	ContentRange       = "Content-Range"
	Connection         = "Connection"
	AcceptRanges       = "Accept-Ranges"
	AmzBucketRegion    = "X-Amz-Bucket-Region"

    override fun contentType(): MediaType? {
      return "text/plain".toMediaType()
    }

    override fun contentLength(): Long {
      return chunk!!.size * 8L
    }

    override fun writeTo(sink: BufferedSink) {
      try {
        var i = 0
        while (i < contentLength()) {
          sink.write(chunk!!)
          sink.flush()
          Thread.sleep(100)
          i += chunk.size

        headers.removeAll(name)
      }

    fun body(body: Buffer) = body(body.toMockResponseBody())

    fun body(body: MockResponseBody) =
      apply {
        setHeader("Content-Length", body.contentLength)
        this.body = body
      }

    /** Sets the response body to the UTF-8 encoded bytes of [body]. */
    fun body(body: String): Builder = body(Buffer().writeUtf8(body))

		return
	}

	// Content-Length is required and should be non-zero
	if r.ContentLength <= 0 {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrMissingPart), r.URL)
		return
	}

	complMultipartUpload := &CompleteMultipartUpload{}
	if err = xmlDecoder(r.Body, complMultipartUpload, r.ContentLength); err != nil {
		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
		return
	}

	if !s.IsValid(w, r) {
		return
	}
	volume := r.Form.Get(storageRESTVolume)
	filePath := r.Form.Get(storageRESTFilePath)

	buf := make([]byte, r.ContentLength)
	_, err := io.ReadFull(r.Body, buf)
	if err != nil {
		s.writeErrorResponse(w, err)
		return
	}
	err = s.getStorage().AppendFile(r.Context(), volume, filePath, buf)
	if err != nil {

 *  New: `Headers.of(Map)` creates headers from a Map.


## Version 2.2.0

_2014-12-30_

 *  **`RequestBody.contentLength()` now throws `IOException`.**
    This is a source-incompatible change. If you have code that calls
    `RequestBody.contentLength()`, your compile will break with this
    update. The change is binary-compatible, however: code compiled

   * be consumed only once.
   *
   * This always returns an unreadable [ResponseBody], which may implement [ResponseBody.contentType] and [ResponseBody.contentLength], on responses returned from [cacheResponse], [networkResponse],
   * and [priorResponse].
   */
  @get:JvmName("body") val body: ResponseBody,
  /**