code: public boolean addFlowElement(MapElement fe) {
  		if (fe instanceof ExceptionHandler) {
  			exceptionHandler = (ExceptionHandler) fe;
  			return true;
  		} else if (fe instanceof InvocationResultExpression) {
  			if (results == null) {
  				results = new ArrayList();
  			}
  			results.add(fe);
  			return true;
  		}
  		return false;
  	}
docs: Adds invocation results and exception handlers.
  
  @param fe
  @return