code: func NewFormatter(verb, format string) (Formatter, error) {
  	switch verb {
  	case "color":
  		return newColorFormatter(format)
  	case "id":
  		return newSequenceFormatter(format), nil
  	case "level":
  		return newLevelFormatter(format), nil
  	case "message":
  		return newMessageFormatter(format), nil
  	case "module":
  		return newModuleFormatter(format), nil
  	case "shortfunc":
  		return newShortFuncFormatter(format), nil
  	case "time":
  		return newTimeFormatter(format), nil
  	default:
  		return nil, fmt.Errorf("unknown verb: %s", verb)
  	}
  }
docs: // NewFormatter creates the formatter for the provided verb. When a format is
  // not provided, the default format for the verb is used.