This is a fairly bare bones template you can start with. You can run this session relevance in WebReports, presentation debugger, as an API call etc. If you need more guidance on this let me know.
(it as string & " MB") of (it / (1024 * 1024)) of sum of download sizes of source fixlets of components of component groups of bes fixlet whose (baseline flag of it AND name of it as lowercase = "the name of you baseline in lowercase")
I do it as lowercase to keep things consistent and reduce case based errors