code: func stringToTimeHookFunc() mapstructure.DecodeHookFunc {
  	return func(
  		f reflect.Type,
  		t reflect.Type,
  		data interface{}) (interface{}, error) {
  		if f.Kind() != reflect.String {
  			return data, nil
  		}
  		if t != reflect.TypeOf(time.Now()) {
  			return data, nil
  		}
  
  		// Convert it by parsing
  		return time.Parse(time.RFC3339, data.(string))
  	}
  }
docs: // stringToTimeHookFunc returns a function that converts strings to a time.Time
  // value.