Ticket [#20837](https://trac.torproject.org/projects/tor/ticket/20837) for `iat-mode` changes. ([diff](https://trac.torproject.org/projects/tor/wiki/doc/MetricsTimeline?action=diff&version=41)) URL: https://trac.torproject.org/projects/tor/wiki/doc/MetricsTimeline?version=41