Function actors_with_access 

pub fn actors_with_access<'a>(
    events: &'a [DisclosureEvent],
    commitment: &PayloadCommitment,
) -> Vec<&'a str>

The distinct actors who had access to a payload (recipients + any acting delegates) — the set the leak must be within. If the perpetrator demonstrably knows something disclosed only here, the leak is one of these.