run method
Runs this command.
The return value is wrapped in a Future if necessary and returned by
CommandRunner.runCommand.
Implementation
@override
void run() async {
  final timeout = int.parse(argResults!['timeout']);
  if (timeout < 1) {
    throw UsageException(
        'API usage error:', 'timeout must be greater than zero');
  }
  final multicastProbe = MulticastProbe();
  await multicastProbe.probe();
  print(multicastProbe.onvifDevices);
}