init method
Implementation
Future<void> init() async {
final dir = await getApplicationDocumentsDirectory();
final logDir = Directory('${dir.path}/log');
if (!await logDir.exists()) {
await logDir.create(recursive: true);
}
final fileName = '.${DateTime.now().toString().split(" ").first}.log';
_file = File('${logDir.path}/$fileName');
}