code: func (self ErrorList) Error() string {
  	switch len(self) {
  	case 0:
  		return "no errors"
  	case 1:
  		return self[0].Error()
  	}
  	return fmt.Sprintf("%s (and %d more errors)", self[0].Error(), len(self)-1)
  }
docs: // Error implements the Error interface.