* lookup IP addresses. Most custom [Dns] implementations should delegate to this instance.
     */
    @JvmField
    val SYSTEM: Dns = DnsSystem()

    private class DnsSystem : Dns {
      override fun lookup(hostname: String): List<InetAddress> {
        try {
          return InetAddress.getAllByName(hostname).toList()
        } catch (e: NullPointerException) {