* as attempting IPv6 first, can make such decisions.
   */
  @ExperimentalOkHttpApi
  enum class DnsClass(val type: Int) {
    IPV4(TYPE_A),
    IPV6(TYPE_AAAA),
  }

  @ExperimentalOkHttpApi
  companion object {
    const val TYPE_A = 1
    const val TYPE_AAAA = 28

    /**
     * Adapt an AsyncDns implementation to Dns, waiting until onComplete is received