splitSnapshotAffectedStructs = (transaction, snapshot) => {
  const meta = map.setIfUndefined(transaction.meta, splitSnapshotAffectedStructs, set.create);
  const store = transaction.doc.store; // check if we already split for this snapshot

  if (!meta.has(snapshot)) {
    snapshot.sv.forEach((clock, client) => {
      if (clock < getState(store, client)) {
        getItemCleanStart(transaction, createID(client, clock));
      }
    });
    iterateDeletedStructs(transaction, snapshot.ds, item => {});
    meta.add(snapshot);
  }
}
@param {Transaction} transaction
@param {Snapshot} snapshot