private fun createTunnel(): Request? {
    var nextRequest = tunnelRequest!!
    // Make an SSL Tunnel on the first message pair of each SSL + proxy connection.
    val url = route.address.url
    val requestLine = "CONNECT ${url.toHostHeader(includeDefaultPort = true)} HTTP/1.1"
    while (true) {
      val source = this.source!!
      val sink = this.sink!!
      val tunnelCodec =
        Http1ExchangeCodec(