code: func (list ErrorList) Error() string {
  	if len(list) == 0 {
  		return "Empty ErrorList"
  	}
  	var b strings.Builder
  	for _, err := range list {
  		fmt.Fprintln(&b, err)
  	}
  	return b.String()
  }
docs: // Error calls fmt.Println for of every error in the list
  // and returns the concernated text.
  // Can be called for a nil ErrorList.