RulesRepository repo = getRulesRepository();
AssetItem asset = repo.loadAssetByUUID( assetId );
Discussion dp = new Discussion();
List<DiscussionRecord> discussion = dp.fromString( asset.getStringProperty( Discussion.DISCUSSION_PROPERTY_KEY ) );
discussion.add( new DiscussionRecord( repo.getSession().getUserID(), StringEscapeUtils.escapeXml( comment ) ) );
asset.updateStringProperty( dp.toString( discussion ), Discussion.DISCUSSION_PROPERTY_KEY, false );
repo.save();
push( "discussion", assetId );
MailboxService.getInstance().recordItemUpdated( asset );