class MyNullReturningAdvice implements NullReturningAdvice {

    @Override
    public Object nullReturning(Method method, Object[] args, Object target) throws Throwable {<FILL_FUNCTION_BODY>}
}

        System.out.println("Null Returning method " + method.getName() + " is called.");
        return "hello default value";
    
<no_super_class>