format method
Implementation
String format() {
final ts =
'${timestamp.hour.toString().padLeft(2, '0')}:'
'${timestamp.minute.toString().padLeft(2, '0')}:'
'${timestamp.second.toString().padLeft(2, '0')}';
final dataStr = data != null ? ' | $data' : '';
return '[$ts] ${level.prefix}: $message$dataStr';
}