There is a new API contentBlocker(withIdentifier:blockedResourcesWith:on:) in osx10.15
But as with other related updates the documentation is lacking.
Specifically, how does this work and how to get it to work?
Do I need to implement my own content blocker?
If so, then how does the communication between the content blocker and the safari app extension work / what needs to be configured to make that communication work?
Would be nice to have this implemented before the 10.15 actually goes live...