open fun priorResponse(priorResponse: Response?) = commonPriorResponse(priorResponse)

    @ExperimentalOkHttpApi
    open fun trailers(trailersFn: (() -> Headers)): Builder = commonTrailers(trailersFn)

    open fun sentRequestAtMillis(sentRequestAtMillis: Long) =
      apply {
        this.sentRequestAtMillis = sentRequestAtMillis
      }

  }

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

fun Response.Builder.commonTrailers(trailersFn: (() -> Headers)) =
  apply {
    this.trailersFn = trailersFn
  }

fun Response.Builder.commonBody(body: ResponseBody) =
  apply {
    this.body = body
  }

fun Response.Builder.commonNetworkResponse(networkResponse: Response?) =

    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",

    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

	// only the last chunk is zero-sized.
	if len(cr.buffer) == 0 {
		if cr.debug {
			fmt.Println("EOF. Reading Trailers:", cr.trailers)
		}
		if cr.trailers != nil {
			err = cr.readTrailers()
			if cr.debug {
				fmt.Println("trailers returned:", err, "now:", cr.trailers)
			}
			if err != nil {
				cr.err = err
				return 0, err
			}
		}
		cr.err = io.EOF
		return n, cr.err
	}

  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)
  }