Function caller_is 

fn caller_is(r: &LogRecord, want: &str) -> bool

The executor log’s caller is the catalog’s principal: root, user:<uid>, user:<uid>@<session> or user:<uid>@- (no session), or agent:<name> (an agent’s own principal, §11). Whether a log record was sent by want: agent:<name> is the agent’s request (it acts for its user, §11); anything else is the actor’s own, sent by no agent.