`node` needs to be swapped with `parent` here, otherwise the
`power_level` and `age` in a `TieBreaker` inserted on the following line
are always equal, because both sides are the values for `node` rather
than a different value of `parent` on each iteration, and so the only
thing that could possibly be different is the `event_id` because that's
correctly set to `parent`. This is why I was observing tiebreaks always
being sorted by `event_id` and experiencing incorrectly resolved states.
35e459d86e