fun readResponseHeaders(expectContinue: Boolean): Response.Builder?

  @Throws(IOException::class)
  fun reportedContentLength(response: Response): Long

  @Throws(IOException::class)
  fun openResponseBodySource(response: Response): Source

  /** Returns the trailers after the HTTP response. May be empty. */
  @Throws(IOException::class)
  fun trailers(): Headers

  /**

  override fun reportedContentLength(response: Response): Long {
    return when {
      !response.promisesBody() -> 0L
      else -> response.headersContentLength()
    }
  }

  override fun openResponseBodySource(response: Response): Source {
    return stream!!.source
  }

  override fun trailers(): Headers {
    return stream!!.trailers()
  }

  override fun cancel() {
    canceled = true

  fun openResponseBody(response: Response): ResponseBody {
    try {
      val contentType = response.header("Content-Type")
      val contentLength = codec.reportedContentLength(response)
      val rawSource = codec.openResponseBodySource(response)
      val source = ResponseBodySource(rawSource, contentLength)
      return RealResponseBody(contentType, contentLength, source.buffer())
    } catch (e: IOException) {

    return when {
      !response.promisesBody() -> 0L
      response.isChunked -> -1L
      else -> response.headersContentLength()
    }
  }

  override fun openResponseBodySource(response: Response): Source {
    return when {
      !response.promisesBody() -> newFixedLengthSource(0)
      response.isChunked -> newChunkedSource(response.request.url)
      else -> {