util/errors/error.go
func (e Error) Error() string {
	if msg, ok := Message(e); ok {
		return fmt.Sprintf("%s (%d)", msg, e)
	}
	return "unknown error"
}
func (e Error) Error() string {
	if msg, ok := Message(e); ok {
		return fmt.Sprintf("%s (%d)", msg, e)
	}
	return "unknown error"
}
func ( e Error ) Error ( ) string { if msg , ok := Message ( e ) ; ok { return fmt . Sprintf ( " " , msg , e ) } return " " }
// Error returns an error message of a given error.
Error returns an error message of a given error .