val tlsFallbackScsv = "TLS_FALLBACK_SCSV"
    val supportedCiphers = listOf(*handshakeCertificates.sslSocketFactory().supportedCipherSuites)
    if (!supportedCiphers.contains(tlsFallbackScsv)) {
      // This only works if the client socket supports TLS_FALLBACK_SCSV.
      return
    }
    server.useHttps(handshakeCertificates.sslSocketFactory())
    server.enqueue(MockResponse(socketPolicy = FailHandshake))