error.go
func Wrap(err error, text ...string) Error {
	return causer(newError(nil, err, text...))
}
func Wrap(err error, text ...string) Error {
	return causer(newError(nil, err, text...))
}
func Wrap ( err error , text ... string ) Error { return causer ( newError ( nil , err , text ... ) ) }
// Wrap returns an error that wraps err, optionally annotating
// with the message text.
Wrap returns an error that wraps err optionally annotating with the message text .