Getting Response Headers from Apex Web Service Response with PL/SQL

I have to get the response headers of my "apex_web_service.make_rest_request" request.

I know that it was possible with the "UTL_HTTP" package, as documented here: https://docs.oracle.com/database/121/ARPLS/u_http.htm#BHAHDHHB

But how can I do this with "apex_web_service"? Is it even possible, as I can't find it in this documentation? http://docs.oracle.com/database/121/AEAPI/apex_web_service.htm#AEAPI537

Thanks in advance for your answer(s)!