init method
Implementation
Future<void> init() async {
_wanExternalService =
await device.getService("urn:upnp-org:serviceId:WANIPConn1");
_wanCommonService =
await device.getService("urn:upnp-org:serviceId:WANCommonIFC1");
_wanEthernetLinkService =
await device.getService("urn:upnp-org:serviceId:WANEthLinkC1");
return;
}