code: public void resolveAdviceBeanClass(AspectRule aspectRule) throws IllegalRuleException {
          String beanIdOrClass = aspectRule.getAdviceBeanId();
          if (beanIdOrClass != null) {
              Class<?> beanClass = resolveBeanClass(beanIdOrClass, aspectRule);
              if (beanClass != null) {
                  aspectRule.setAdviceBeanClass(beanClass);
                  reserveBeanReference(beanClass, aspectRule);
              } else {
                  reserveBeanReference(beanIdOrClass, aspectRule);
              }
          }
      }
docs: Resolve bean class for the aspect rule.
  
  @param aspectRule the aspect rule
  @throws IllegalRuleException if an illegal rule is found