String lastLocalRevisionId = lastLocalRevision != -1 ? String.valueOf(lastLocalRevision) : "FIRST";
FeatureDiffReader localChanges = fs.getDifferences(lastLocalRevisionId,
newLocalRevisionId, ff.id(changedFids), null);
while (localChanges.hasNext()) {
FeatureDiff fd = localChanges.next();
FeatureId diffFeatureId = ff.featureId(fd.getID());
if (fd.getState() == FeatureDiff.INSERTED) {
throw new GSSException(
"A new locally inserted feature has the same "
+ "id as a modified feature coming from Central, this is impossible, "
+ "there is either a bug in ID generation or someone manually tampered with it!");