interface ExchangeCodec {
  /** The connection or CONNECT tunnel that owns this codec. */
  val carrier: Carrier

  /** Returns an output stream where the request body can be streamed. */
  @Throws(IOException::class)
  fun createRequestBody(
    request: Request,
    contentLength: Long,
  ): Sink

  /** This should update the HTTP engine's sentRequestMillis field. */
  @Throws(IOException::class)
  fun writeRequestHeaders(request: Request)