code: public void updateChangeLog(final Principal user, final Verb verb, final String linkType, final String linkId, final String sourceUuid, final String targetUuid) {
  
  		if ((Settings.ChangelogEnabled.getValue() || Settings.UserChangelogEnabled.getValue())) {
  
  			final JsonObject obj = new JsonObject();
  
  			obj.add("time",     toElement(System.currentTimeMillis()));
  			obj.add("userId",   toElement(user.getUuid()));
  			obj.add("userName", toElement(user.getName()));
  			obj.add("verb",     toElement(verb));
  			obj.add("rel",      toElement(linkType));
  			obj.add("relId",    toElement(linkId));
  			obj.add("source",   toElement(sourceUuid));
  			obj.add("target",   toElement(targetUuid));
  
  			if (Settings.ChangelogEnabled.getValue()) {
  				changeLog.append(obj.toString());
  				changeLog.append("\n");
  			}
  
  			if (Settings.UserChangelogEnabled.getValue()) {
  
  				// remove user for user-centric logging to reduce redundancy
  				obj.remove("userId");
  				obj.remove("userName");
  
  				appendUserChangelog(user.getUuid(), obj.toString());
  			}
  		}
  	}
docs: Update *relationship* changelog for Verb.create