code: func TooManyItems(name, in string, max int64) *Validation {
  	msg := fmt.Sprintf(maxItemsFail, name, in, max)
  	if in == "" {
  		msg = fmt.Sprintf(maxItemsFailNoIn, name, max)
  	}
  
  	return &Validation{
  		code:    MaxItemsFailCode,
  		Name:    name,
  		In:      in,
  		message: msg,
  	}
  }
docs: // TooManyItems error for when an array contains too many items