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

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

    /** Don't trust the client during the SSL handshake. */
    public fun failHandshake(): Builder =
      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",

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

  @Test
  fun worksIfTrailersSet() {
    val response =
      newResponse("".toResponseBody()) {
        trailers(
          object : TrailersSource {
            override fun get() = Headers.headersOf("a", "b")
          },
        )
      }

    assertThat(response.trailers()["a"]).isEqualTo("b")
  }

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

  fun enqueueTrailers(trailers: Headers) {
    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

  /**

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, "")
		}

			req.Trailer.Add(key, "")
		}
	} else {
		req.Trailer = nil
	}
	return &s3UnsignedChunkedReader{
		trailers: req.Trailer,
		reader:   bufio.NewReader(req.Body),
		buffer:   make([]byte, 64*1024),
	}, ErrNone
}

// Represents the overall state that is required for decoding a
// AWS Signature V4 chunked reader.
type s3UnsignedChunkedReader struct {
	reader   *bufio.Reader
	trailers http.Header

	buffer []byte

 */
package okhttp3

import okio.IOException

/**
 * Returns the trailers that follow an HTTP response, blocking if they aren't ready yet.
 * Implementations of this interface should respond to [Call.cancel] by immediately throwing an
 * [IOException].
 *
 * Most callers won't need this interface, and should use [Response.trailers] instead.
 *

      .build()

  @Test
  fun trailersHttp1() {
    trailers(Protocol.HTTP_1_1)
  }

  @Test
  fun trailersHttp2() {
    trailers(Protocol.HTTP_2)
  }

  private fun trailers(protocol: Protocol) {
    enableProtocol(protocol)

    server.enqueue(
      MockResponse
        .Builder()
        .addHeader("h1", "v1")
        .trailers(headersOf("t1", "v2"))
        .body(protocol, "Hello")

     */
    fun responseBodyComplete(trailers: Headers) {
      if (state == STATE_CLOSED) return
      if (state != STATE_READING_RESPONSE_BODY) throw IllegalStateException("state: $state")

      detachTimeout(timeout)

      this@Http1ExchangeCodec.trailers = trailers
      state = STATE_CLOSED
      if (trailers.size > 0) {
        client?.cookieJar?.receiveHeaders(url, trailers)
      }
    }
  }

    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)
  }