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 {
  await initializeOnvif();
  try {
    final systemDateAndTime = await deviceManagement.getSystemDateAndTime();
    print(systemDateAndTime);
  } on DioError catch (err) {
    throw UsageException('API usage error:', err.usage);
  }
}