code: func MultiError(errors ...error) cli.MultiError {
  	nonNilErrs := []error{}
  	for _, e := range errors {
  		if e != nil {
  			nonNilErrs = append(nonNilErrs, e)
  		}
  	}
  
  	return cli.NewMultiError(nonNilErrs...)
  }
docs: // MultiError loops over all given errors unpacks them and then creates a new
  // MultiError for non-nil entries.