((ChangeSummaryImpl) changeSummary).summarize();
ChangeDescription changeDescription = (ChangeDescription) changeSummary;
Iterator createdDataObjects = changeDescription.getObjectsToDetach().iterator();
deletedDataObjects = changeDescription.getObjectsToAttach();
EMap objectChanges = changeDescription.getObjectChanges();
modifiedDataObjects = objectChanges.keySet(); // may contain DO(s) from createdDataObjects and/or deletedDataObjects
/*
* 6-2. Prepare to compute (X)Path
* input: changeSummary
* output: rootResource