if r := cmp.Compare(a.Revision, b.Revision); r != 0 {
			return r
		}
		return cmp.Compare(a.Tag, b.Tag)
	})

	switch outputFormat {
	case util.JSONFormat, util.YamlFormat:
		return printJSONYAML(writer, tags, outputFormat)
	case util.TableFormat:
	default:
		return fmt.Errorf("unknown format: %s", outputFormat)
	}
	w := new(tabwriter.Writer).Init(writer, 0, 8, 1, ' ', 0)