fun headers(headers: Headers) =
      apply {
        this.headers = headers.newBuilder()
      }

    /** Sets the trailers and returns this. */
    fun trailers(trailers: Headers) =
      apply {
        this.trailers = trailers.newBuilder()
      }

    /** Sets the socket policy and returns this. */
    fun socketPolicy(socketPolicy: SocketPolicy) =
      apply {

  @JvmName("-deprecated_getTrailers")
  @Deprecated(
    message = "moved to var",
    replaceWith = ReplaceWith(expression = "trailers"),
    level = DeprecationLevel.ERROR,
  )
  fun getTrailers(): Headers = trailers

  fun setTrailers(trailers: Headers) = apply { this.trailers = trailers }

  @JvmName("-deprecated_getSocketPolicy")
  @Deprecated(
    message = "moved to var",

func newSignV4ChunkedReader(req *http.Request, trailer bool) (io.ReadCloser, APIErrorCode) {
	cred, seedSignature, region, seedDate, errCode := calculateSeedSignature(req, trailer)
	if errCode != ErrNone {
		return nil, errCode
	}

	if trailer {
		// Discard anything unsigned.
		req.Trailer = make(http.Header)
		trailers := req.Header.Values(awsTrailerHeader)
		for _, key := range trailers {
			req.Trailer.Add(key, "")
		}

func newUnsignedV4ChunkedReader(req *http.Request, trailer bool) (io.ReadCloser, APIErrorCode) {
	if trailer {
		// Discard anything unsigned.
		req.Trailer = make(http.Header)
		trailers := req.Header.Values(awsTrailerHeader)
		for _, key := range trailers {
			req.Trailer.Add(key, "")
		}
	} else {
		req.Trailer = nil
	}
	return &s3UnsignedChunkedReader{
		trailers: req.Trailer,
		reader:   bufio.NewReader(req.Body),

    assertThat(response.trailers()).isEmpty()
  }

  @Test
  fun testFailsIfTrailersNotSet() {
    val response =
      newResponse("".toResponseBody()) {
        // All live paths (Http1, Http2) in OkHttp do this
        trailers { error("trailers not available") }
      }

    assertFailsWith<IllegalStateException>(message = "trailers not available") {
      response.trailers()
    }
  }

    if (flushHeaders) {
      connection.flush()
    }
  }

  fun enqueueTrailers(trailers: Headers) {
    this.withLock {
      check(!sink.finished) { "already finished" }
      require(trailers.size != 0) { "trailers.size() == 0" }
      this.sink.trailers = trailers
    }
  }

  fun readTimeout(): Timeout = readTimeout

  fun writeTimeout(): Timeout = writeTimeout

  private val Request.isChunked: Boolean
    get() = "chunked".equals(header("Transfer-Encoding"), ignoreCase = true)

  /**
   * Received trailers. Null unless the response body uses chunked transfer-encoding and includes
   * trailers. Undefined until the end of the response body.
   */
  private var trailers: Headers? = null

  /** Returns true if this connection is closed. */
  val isClosed: Boolean
    get() = state == STATE_CLOSED

      else -> response.headersContentLength()
    }
  }

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

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

  override fun cancel() {
    canceled = true
    stream?.closeLater(ErrorCode.CANCEL)
  }

  companion object {
    private const val CONNECTION = "connection"

    val request =
      Request.Builder()
        .url("http://square.com/")
        .header("TE", "trailers")
        .build()
    val expected =
      headerEntries(
        ":method",
        "GET",
        ":path",
        "/",
        ":scheme",
        "http",
        "te",
        "trailers",
      )
    assertThat(http2HeadersList(request)).isEqualTo(expected)
  }

    val mockResponse =
      MockResponse.Builder()
        .socketPolicy(DoNotReadRequestBody(ErrorCode.NO_ERROR.httpCode))
        .trailers(headersOf("caboose", "xyz"))

    // Trailers always work for HTTP/2, but only for chunked bodies in HTTP/1.
    if (http2) {
      mockResponse.body("abc")
    } else {
      mockResponse.chunkedBody("abc", 1)
    }