contentLength: Long,
  ): Sink = stream!!.sink

  override fun writeRequestHeaders(request: Request) {
    if (stream != null) return

    val hasRequestBody = request.body != null
    val requestHeaders = http2HeadersList(request)
    stream = http2Connection.newStream(requestHeaders, hasRequestBody)
    // We may have been asked to cancel while creating the new stream and sending the request