code: protected static Object checkAOP(Object aop) {
  		if (aop != null && aop instanceof MethodInterceptor)
  			return new BeanBox().setTarget(aop).setPureValue(true);
  		else
  			return aop;
  	}
docs: If aop is a instance of Aop alliance Interceptor, wrap it to a BeanBox and
  set as purevalue, otherwise direct return it (class or BeanBox)