code: public String extractModel(XLog log) {
  		XAttribute attribute = log.getAttributes().get(KEY_MODEL);
  		if (attribute == null) {
  			return null;
  		} else {
  			return ((XAttributeLiteral) attribute).getValue();
  		}
  	}
docs: Extracts the lifecycle model identifier from a given log.
  
  @param log
  Event log.
  @return Lifecycle model identifier string.