ReadonlywrittenRecords inserted, or rewritten because the source changed them.
ReadonlypreservedRecords left untouched because they hold unsynchronised local work.
ReadonlyunchangedRecords left untouched because the source serves them under the marker already stored.
ReadonlyremovedSynchronised records removed because the source served them as tombstones.
ReadonlyseenThe key of every record this batch named, once its identity was resolved — written,
unchanged or preserved alike. What a complete pull never named is what sweepSynced
may remove.
What one bulk pull actually did to the store.