if (connectionSpec.supportsTlsExtensions) {
        Platform.get().configureTlsExtensions(sslSocket, address.url.host, address.protocols)
      }

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