code: public Collection<XAttribute> getDefinedAttributes() {
  		if (allAttributes == null) {
  			// create collection on demand
  			allAttributes = new HashSet<XAttribute>();
  			allAttributes.addAll(getLogAttributes());
  			allAttributes.addAll(getTraceAttributes());
  			allAttributes.addAll(getEventAttributes());
  			allAttributes.addAll(getEventAttributes());
  		}
  		return allAttributes;
  	}
docs: Returns the collection of attributes defined by this extension for any
  log elements (archive-, log-, trace-, event-, and meta-attributes).