code: func ValidatePackagePrefix(p string) (string, error) {
  	p = strings.TrimSuffix(p, "/")
  	if p != "" {
  		if err := validatePathishString(p, "package prefix"); err != nil {
  			return "", err
  		}
  	}
  	return p, nil
  }
docs: // ValidatePackagePrefix normalizes and validates a package prefix.
  //
  // A prefix is basically like a package name, except it is allowed to have '/'
  // at the end (such trailing '/' is stripped by this function), and it can be
  // an empty string or "/" (to indicate the root of the repository).