code: public List<String> extractModelReferences(XAttributable target) {
  		ArrayList<String> modelReferences = new ArrayList<String>();
  		XAttributeLiteral modelReferenceAttribute = (XAttributeLiteral) target
  				.getAttributes().get(KEY_MODELREFERENCE);
  		if (modelReferenceAttribute != null) {
  			String refString = modelReferenceAttribute.getValue().trim();
  			for (String reference : refString.split("\\s")) {
  				modelReferences.add(reference.trim());
  			}
  		}
  		return modelReferences;
  	}
docs: Retrieves the list of model references which describe a log element
  (archive, log, trace, event, attribute).
  
  @param target
  Any log element (i.e., archive, log, trace, event, or
  attribute) to be queried.
  @return The list of model references, as a list of strings, referred to
  by this element.