code: func ParseLevel(level string) (Level, error) {
  	level = strings.ToLower(level)
  	for _, l := range levels {
  		if strings.ToLower(l.String()) == level {
  			return l, nil
  		}
  	}
  	return Level(0), fmt.Errorf("unrecognized log level: %s", level)
  }
docs: // ParseLevel parses a log level string to log level.