formatter method
日志格式化
Implementation
String formatter(LogRecord record) {
final time = record.dateTime.format(DateFormats.time);
final timeSuffix = '${record.dateTime.millisecond.toString().padLeft(3, '0')}${record.dateTime.microsecond.toString().padLeft(3, '0')}';
return '$time.$timeSuffix [${record.level.short ?? record.level.name}] ${record.name}: ${record.toMultiLineString().join('\n')}';
}