Provisioned and allocated capacity of a volume query via REST API

I am attempting to make a couple of calls - to find out how much capacity is consumed per LUN. However, that info does not seem to be provided via the call. Could you please help me with identifying if I am missing anything here ?

Upon a quick search within the community - I have found few already implemented solutions by parsing xml data - but wanted to see if I can obtain the same info via Rest API calls

Thank you !