Read a run's branch order, or an empty index when the source cannot offer one (runHistory is optional — a driver that has no history to walk says so by omitting it, and every comparison then falls back to clocks).
runHistory
Read a run's branch order, or an empty index when the source cannot offer one (
runHistoryis optional — a driver that has no history to walk says so by omitting it, and every comparison then falls back to clocks).