Custom Service creating webservices

Hi there, 

I have followed the following link to create a custom webservice: 

http://vishwad365fo.blogspot.com/2018/05/custom-service-to-create-sales-order.html

This works fantastic. This works with a list object. I am wondering if there is a way to send through a parameter of another class in such a manner that the JSON input will look like the following:

(The delivery section refers to the object I want to pass) 

Thanks!