code: public BeanO getCallbackBeanO()
      {
          BeanO result = ivCallbackBeanOStack.peek();
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled())
              Tr.debug(tc, "getCallbackBeanO: " + result);
          return result;
      }
docs: Gets a reference to the bean that the container is currently processing
  via a business method or lifecycle callback.
  
  @return the callback bean, or null if the container is not processing a
  bean