code: public XID extractID(XAttributable element) {
  		XAttribute attribute = element.getAttributes().get(KEY_ID);
  		if (attribute == null) {
  			return null;
  		} else {
  			return ((XAttributeID) attribute).getValue();
  		}
  	}
docs: Retrieves the id of a log data hierarchy element, if set by this
  extension's id attribute.
  
  @param element
  Log hierarchy element to extract name from.
  @return The requested element id.