replacement.addSimpleExtension(new QName(
"http://activitystrea.ms/spec/1.0/", "verb", "activity"),
"deleted");
// add reference to deleting id
replacement.addCategory(Common.MENTION_URN,
Common.toEntryUrn(feedId, deletingId), "Mention");
// write the entry
storage.updateEntry(feedId, deletedId, replacement.getUpdated(),
replacement.toString());