List<Action<R>> actionsForRegion = e.getValue();
// sort based on the row id - this helps in the case where we reach the
// end of a region, so that we don't have to try the rest of the
// actions in the list.
Collections.sort(actionsForRegion);
Row action;
List<Action<R>> mutations = new ArrayList<Action<R>>();
for (Action<R> a : actionsForRegion) {
action = a.getAction();
int originalIndex = a.getOriginalIndex();