client = new OkHttpClient.Builder()
        .connectionSpecs(Collections.singletonList(spec))
        .sslSocketFactory(customSslSocketFactory, trustManager)
        .build();
  }

  /**
   * Returns the VM's default SSL socket factory, using {@code trustManager} for trusted root
   * certificates.
   */
  private SSLSocketFactory defaultSslSocketFactory(X509TrustManager trustManager)

  // System.setProperty("javax.net.debug", "ssl:handshake:verbose");
  Security.insertProviderAt(Conscrypt.newProviderBuilder().provideTrustManager().build(), 1)
  println("Running tests using ${Platform.get()} ${System.getProperty("java.vm.version")}")

  // https://github.com/tlswg/tls13-spec/wiki/Implementations
  val urls =
    listOf(
      "https://enabled.tls13.com",
      "https://www.howsmyssl.com/a/check",
      "https://tls13.cloudflare.com",

  return Client(
    userAgent = "OkHttp",
    version = version,
    enabled = enabled,
  )
}

fun currentVm(ianaSuites: IanaSuites): Client {
  return systemDefault(
    name = System.getProperty("java.vm.name"),
    version = System.getProperty("java.version"),
    ianaSuites = ianaSuites,
  )
}

fun conscrypt(ianaSuites: IanaSuites): Client {
  val version = Conscrypt.version()
  return systemDefault(

    <useClassPathOnly />
    <option name="MAIN_CLASS_NAME" value="" />
    <option name="METHOD_NAME" value="" />
    <option name="TEST_OBJECT" value="tags" />
    <option name="VM_PARAMETERS" value="-ea -Djunit.jupiter.extensions.autodetection.enabled=true" />
    <option name="PARAMETERS" value="" />
    <option name="TEST_SEARCH_SCOPE">
      <value defaultName="wholeProject" />
    </option>

    in 161..181 -> "8.1.12.v20180117"
    in 191..242 -> "8.1.13.v20181017"
    else -> null
  }
}

/**
 * Returns the alpn-boot version specific to this OpenJDK 8 JVM, or null if this is not a Java 8 VM.
 * https://github.com/xjdr/xio/blob/master/alpn-boot.gradle
 */
fun alpnBootVersion(): String? {
  val version = System.getProperty("alpn.boot.version")

  if (version != null) {
    return version
  }