}

  /**
   * Configure TLS extensions on `sslSocket` for `route`.
   */
  open fun configureTlsExtensions(
    sslSocket: SSLSocket,
    hostname: String?,
    protocols: List<@JvmSuppressWildcards Protocol>,
  ) {
  }

  /** Called after the TLS handshake to release resources allocated by [configureTlsExtensions]. */
  open fun afterHandshake(sslSocket: SSLSocket) {
  }

    connectionSpec: ConnectionSpec,
  ) {
    val address = route.address
    var success = false
    try {
      if (connectionSpec.supportsTlsExtensions) {
        Platform.get().configureTlsExtensions(sslSocket, address.url.host, address.protocols)
      }

      // Force handshake. This can throw!
      sslSocket.startHandshake()
      // block for session establishment

            sslSocket.wantClientAuth = true
          }
          openClientSockets.add(socket)

          if (protocolNegotiationEnabled) {
            Platform.get().configureTlsExtensions(sslSocket, null, protocols)
          }

          sslSocket.startHandshake()

          if (protocolNegotiationEnabled) {
            val protocolString = Platform.get().getSelectedProtocol(sslSocket)