val heldCertificate = HeldCertificate.Builder().build()
    builder = builder.heldCertificate(heldCertificate, heldCertificate.certificate)
    builder = builder.addTrustedCertificate(heldCertificate.certificate)
    builder = builder.addPlatformTrustedCertificates()
    val handshakeCertificates: HandshakeCertificates = builder.build()
  }

  @Test
  fun heldCertificate() {

      HandshakeCertificates
        .Builder()
        .heldCertificate(serverCertificate)
        .build()
    val clientCertificates =
      HandshakeCertificates
        .Builder()
        .addTrustedCertificate(serverCertificate.certificate)
        .build()
    client =
      client
        .newBuilder()
        .sslSocketFactory(clientCertificates.sslSocketFactory(), clientCertificates.trustManager)