const val TYPE_A = 1
    const val TYPE_AAAA = 28

    /**
     * Adapt an AsyncDns implementation to Dns, waiting until onComplete is received
     * and returning results if available.
     */
    fun toDns(vararg asyncDns: AsyncDns): Dns =
      Dns { hostname ->
        val allAddresses = mutableListOf<InetAddress>()
        val allExceptions = mutableListOf<IOException>()
        val latch = CountDownLatch(asyncDns.size)