How to get XML and JSON mockesponse at the same time ?

I have created a rest mock service which has JSON response. While sending out Mock requests, it shows only JSON and it's corresponding XML output is not shown. So I created 2 mock responses; one with XML and other JSON. But everytime I execute the request, it gives mock responses SEQUENTIALLY, first time XML response and second time JSON and happens in loop. So do I need to create a groovy script in order to get mock responses in both XML and JSON formats at the same time ???