func (p *tagDiffProcessor) diffOldNew() []string {
	return p.diff(p.oldTagIDs, p.newTagIDs)
}
func (p *tagDiffProcessor) diffOldNew() []string {
	return p.diff(p.oldTagIDs, p.newTagIDs)
}
func ( p * tagDiffProcessor ) diffOldNew ( ) [ ] string { return p . diff ( p . oldTagIDs , p . newTagIDs ) }
// diffOldNew returns any elements of old that were missing in new.
diffOldNew returns any elements of old that were missing in new .