code: func (level LogLevel) String() string {
  	switch level {
  	case PanicLevel:
  		return "panic"
  	case FatalLevel:
  		return "fatal"
  	case ErrorLevel:
  		return "error"
  	case WarnLevel:
  		return "warn"
  	case InfoLevel:
  		return "info"
  	case DebugLevel:
  		return "debug"
  	default:
  		return fmt.Sprintf("unknown(%d)", level)
  	}
  }
docs: // String converts the LogLevel to a string. E.g. PanicLevel becomes "panic".