Codebook Workspace API - News help!

Hi, i'm trying to pull news headlines via the workspace API.

rd.news.get_headlines("LSEG, MSFT.O AND Language:LEN", count=50)

this code works for pulling headlines, but how do i add another filter for "content type" like in the APP NEWS 2.0? i.e. web news, research, transcripts, filings etc. I'd like to filter my query. I tried "ContentType", but that didnt yield any results. Please advise.