root
fun root(runRef: ExtractionRunRef, supersedesRunRef: ExtractionRunRef? = null, passIndex: Int = 0): ExtractionRunLineage
Mints the lineage of a run that starts one: its own root, no parent.
A first extraction of some material takes this. So does a re-extraction that replaces an earlier run without continuing it — pass supersedesRunRef and the supersession is recorded without making the replaced run a parent.